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Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
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5

Physics Laboratory

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

PANEL MEMBERS

David H. Auston, Case Western Reserve University, Chair

Janet S. Fender, Air Force Research Laboratory, Vice Chair

Anthony J. Berejka, Consultant, Huntington, New York

Gary C. Bjorklund, Bjorklund Consulting, Inc.

D. Keith Bowen, Bede Scientific Incorporated

Shirley Chiang, University of California, Davis

Gregory R. Choppin, Florida State University

Leonard S. Cutler, Agilent Technologies

Ronald O. Daubach, OSRAM SYLVANIA Development, Inc.

Paul M. DeLuca, Jr., University of Wisconsin Medical School

Jay M. Eastman, Lucid, Inc.

Stephen D. Fantone, Optikos Corporation

Thomas F. Gallagher, University of Virginia

Daniel J. Larson, Pennsylvania State University

David S. Leckrone, NASA Goddard Space Flight Center

Neville V. Smith, Lawrence Berkeley National Laboratory

Submitted for the panel by its Chair, David H. Auston, and its Vice Chair, Janet S. Fender, this assessment of the fiscal year 2000 activities of the Physics Laboratory is based on site visits by individual panel members, a formal meeting of the panel on March 13-14, 2000, in Gaithersburg, Md., and on documents provided by the laboratory.1

1  

U.S. Department of Commerce, Technology Administration, National Institute of Standards and Technology, Physics Laboratory: Technical Activities 1999, NISTIR 6438, National Institute of Standards and Technology, Gaithersburg, Md., 2000.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

LABORATORY-LEVEL REVIEW

Laboratory Mission

According to the laboratory documentation, the mission of the NIST Physics Laboratory (PL) is to support U.S. industry, government, and academia by providing measurement services and research for electronic, optical, and ionizing radiation technology.

This mission is appropriate to the overall mission of NIST, and the areas of research specified in the PL mission are appropriate to the core competencies of the laboratory. The PL strives to meet its mission through the programs and ongoing projects in its six divisions: Electron and Optical Physics, Atomic Physics, Optical Technology, Ionizing Radiation, Time and Frequency, and Quantum Physics. The first five of these divisions are reviewed by the panel below. The Quantum Physics Division, which is part of JILA, a joint institute of NIST and the University of Colorado, is assessed by a separate subpanel in the final section of this chapter.

The panel notes that NIST's role in measurement and standards for use in commerce is unique and cannot be duplicated by industry or academia. To the extent that the PL continues to focus its activities on this core mission of measurement and standards, it can be assured that its programs will be appropriate to NIST.

Technical Merit and Appropriateness of Work

Overall, the technical merit of ongoing programs and projects in the PL is very high. Many projects are at or define the state of the art, and in some cases, NIST is not just the leader but the dominant force in highly competitive areas of scientific research. Detailed descriptions and assessment of ongoing programs are given in the divisional reviews below.

The panel was briefed by PL personnel on four areas of new or expanding opportunity for the PL: nanotechnology, biophysics, medical physics, and quantum information.

In nanotechnology, the PL is already a world leader in the fabrication and analysis of small structures such as thin magnetic layers. Future plans include better understanding of edge effects in small magnetic and electronic structures and of electron transport and tunneling in ferromagnetic, semiconductor, and superconductor materials. This work would be complementary to ongoing work in other NIST laboratories on single-electron tunneling devices, nanoscale metrology, nanoscale analysis, and other areas.

In biophysics, many PL measurement techniques can be adapted to provide new measurement capabilities for the biological sciences. For example, great potential exists for the use of laser light to isolate and manipulate biological objects such as proteins or enzymes. This opportunity is enhanced by the growing presence of biotechnology firms near Gaithersburg, Maryland, which provides PL with potential partners for its work and a critical mass of interested researchers in the immediate area.

In medical physics, the aging of the baby boom generation will bring greater need for medical diagnostics, treatment, and palliative therapies. It is anticipated that many new techniques involving ionizing radiation, such as the recent introduction of radioactive seed therapy for prostate cancer, will be developed. These will require new standards and measurement techniques to ensure the quality of treatment delivered. New programs would build on the PL's current status as provider of primary standards for the medical use of ionizing radiation.

Quantum information is a highly speculative but potentially high-payoff project that uses NIST's unquestioned world leadership in the manipulation of atoms and atomic states to explore one promising avenue toward quantum computing. Although achieving useful computational ability based on the use

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

of quantum states to store information is an as-yet-uncertain proposition, it is an understatement to say that, if realized, its impact would be profound. Early exploratory research such as this could give the United States a definitive lead in the development and use of such technology. The talent engaged in this effort at NIST is extraordinary and bodes well for important advances.

The panel was highly impressed by the content of all four of these presentations. All represent areas with great potential for economic importance, and all four are areas in which an existing PL expertise base can be built upon to establish new areas of leadership. Most are highly interdisciplinary in nature and will leverage scientific expertise available in other NIST laboratories to achieve accomplishments that would not be realized by any one laboratory alone. These four directions represent appropriate avenues to explore and pursue as PL tries to anticipate future developments so that measurement and standards technologies can be available when industry requires them.

Impact of Programs

The results of PL programs are disseminated widely through various means, such as professional publications, seminars, workshops, and the World Wide Web. The degree to which researchers and programs are tied to their eventual industrial customers varies with the nature of each program, as is appropriate. PL management and staff must continually work to maintain and strengthen ties to industry in such a way as to truly ascertain industry's anticipated needs rather than react to current industry wants.

Several programs discussed—for example, Internet time service and quantum information—raised questions of how intellectual property was handled by PL and NIST in instances that might generate significant direct economic value. Although a certain amount of case-by-case decision making will always be necessary in this area, the current policy seemed a bit too ad hoc. The panel encourages PL and NIST as a whole to develop a better planned, more-thought-out, and more consistent approach to intellectual property management. In the two examples mentioned above, the potential revenue streams might not be insignificant, and thought must be given to an approach to intellectual property that not only is equitable but also provides incentives both to PL and to the individual investigator to pursue intellectual property protection appropriately.

Laboratory Resources

Funding sources for the Physics Laboratory are shown in Table 5.1. As of January 2000, staffing for the Physics Laboratory included 200 full-time permanent positions, of which 168 were for technical professionals. There were also 56 nonpermanent and supplemental personnel, such as postdoctoral research associates and part-time workers.

The pool of scientific talent collected in the laboratory is outstanding by any measure, and a number of staff members are simply unequaled anywhere in their expertise. The panel was particularly pleased to see that the PL is able to recruit and (thus far) retain young researchers of very high quality—a promising development for the future of NIST and the PL.

Although notable progress has been made on facilities needs in some areas, significant capital equipment and facility needs noted in previous reports are still outstanding. Like many other government laboratories, NIST has historically underinvested in facility maintenance and upgrade, and the PL has no long-term plan for capital equipment purchases. Such deficiencies can seriously compromise the PL's ability to compete in recruiting and retaining the most talented scientists. Since its outstanding staff are PL's and NIST's greatest resource, this would gravely affect NIST's ability to carry out its mission. Specific facility and equipment needs are detailed in the divisional reports below.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

TABLE 5.1 Sources of Funding for the Physics Laboratory (in millions of dollars), FY 1997 to FY 2000

Source of Funding

Fiscal Year

1997 (actual)

Fiscal Year

1998 (actual)

Fiscal Year

1999 (actual)

Fiscal Year

2000 (estimated)

NIST-STRS, excluding Competence

29.8

31.2

33.0

32.9

Competence

2.9

1.9

1.6

1.8

ATP

0.8

1.8

1.9

2.2

Measurement Services (SRM production)

0.3

0.2

0.2

0.1

OA/NFG/CRADA

9.6

9.5

10.1

11.6

Other Reimbursable

3.4

3.5

3.6

3.8

Total

46.8

48.1

50.4

52.4

Full-time permanent staff (total)a

206

207

204

200

NOTE: Funding for the NIST Measurement and Standards Laboratories comes from a variety of sources. The laboratories receive appropriations from Congress, known as Scientific and Technical Research and Services (STRS) funding. Competence funding also comes from NIST's congressional appropriations but is allocated by the NIST director's office in multiyear grants for projects that advance NIST's capabilities in new and emerging areas of measurement science. Advanced Technology Program (ATP) funding reflects support from NIST's ATP for work done at the NIST laboratories in collaboration with or in support of ATP projects. Funding to support production of Standard Reference Materials (SRMs) is tied to the use of such products and is classified as Measurement Services. NIST laboratories also receive funding through grants or contracts from other government agencies (OA), from nonfederal government (NFG) agencies, and from industry in the form of Cooperative Research and Development Agreements (CRADAs). All other laboratory funding, including that for Calibration Services, is grouped under “Other Reimbursable.”

a The number of full-time permanent staff is as of January of that fiscal year.

As noted above in “Technical Merit and Appropriateness of Work,” the PL has identified several research areas for new programs that the panel believes represent great opportunities for NIST and potentially great contributions to emerging industries and areas of national priority. However, success in establishing a NIST presence in these areas will require substantial resources to build up necessary infrastructure and expertise. Reprogramming can and should be used to obtain resources for these areas, but reprogramming alone cannot provide the level of investment necessary to begin ambitious new programs such as these. New funding is required to begin adequate programs in these areas. More aggressive advocacy for new funding for the PL, and for the Measurement and Standards Laboratories as a whole, seems appropriate.

DIVISIONAL REVIEWS

Electron and Optical Physics Division
Division Mission

According to division documentation, the mission of the Electron and Optical Physics Division is to develop measurement capabilities needed by emerging electronic and optical technologies, particularly those required for submicron fabrication and analysis.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×
Technical Merit and Appropriateness of Work

The Electron and Optical Physics Division is organized into three groups: the Photon Physics Group, the Far Ultraviolet Physics Group, and the Electron Physics Group. All three groups do world-class work in their respective fields. This work is generally consistent with the NIST mission and national needs in the areas of nanoscience and nanotechnology. The work spans the range from basic theory of magnetism and Bose-Einstein condensates to calibration of multilayers and detectors for industry and for the National Aeronautics and Space Administration (NASA).

The division provides the central national basis for absolute radiometry in the deep-ultraviolet (DUV) and extreme-ultraviolet (EUV) regions of the electromagnetic spectrum, which together span the photon energy range from 5 to 250 eV. The Photon Physics Group, in collaboration with the Optical Technology Division, has developed state-of-the-art measurement capability for characterizing the optical properties of materials in the DUV. This region of the spectrum has always been difficult, since almost all materials absorb this radiation. Thus, there are few suitable refractive materials for wavelengths less than 180 nm, there is a lack of continuous-wave lasers, deleterious optical damage occurs, and there is no laboratory-sized true continuum source available for the entire region. The division is now able to provide DUV transmission and index-of-refraction data on optical materials such as calcium fluoride (CaF2) that are critical to 157-nm lithography. The accuracy (6 ppm) of these measurements of index of refraction matches the stringent requirements for stepper design and has revealed unacceptable supplier-to-supplier index variation in the CaF2. In addition, using the Synchrotron Ultraviolet Radiation Facility (SURF III) the group has developed a new radiometric source calculable to a precision better than 1 percent for all wavelengths greater than 2 nm. Together with absolute cryogenic radiometer (ACR) measurements, a new, improved radiometric source has been achieved in the DUV with an uncertainty of less than 1 percent. Work is also being conducted on the development of damage-resistant, solid-state DUV detectors.

The Photon Physics Group's EUV physics programs are well focused in important directions. The program in EUV optics continues to be of considerable value for the future of the semiconductor industry, given the increasing likelihood that EUV lithography will become a critical technology in this industry in the future. Progress toward making high-reflectivity multilayer films with reflectivity peak matched to the 10.5-nm wavelength of the new krypton (Kr) laser plasma source is significant. Current activities include building up rare-gas cluster and laser plasma sources for pulsed EUV dosimetry and the installation of an ion beam deposition machine for improved-quality EUV mirror coatings. The program in x-ray microtomography of integrated circuits has the long-term promise of providing three-dimensional maps of the elemental and chemical composition of integrated circuits and other small engineered structures. Industrial interest has been expressed by DEC, Intel, and IBM. In the first experiments, submicron resolution was demonstrated on an as-grown integrated circuit interconnect using the advanced photon source (APS) synchrotron radiation ring at Argonne National Laboratory. Recently, work using improved reconstruction algorithms has resulted in improvement by a factor of 2 in image resolution. Another planned improvement is the use of a scintillator combined with 10× optical magnification before the charge-coupled device (CCD) detector array. Although these experiments currently require synchrotron radiation, it is possible that laser plasma x-ray sources could be used in the future.

The Far Ultraviolet Physics Group has completed the upgrade of SURF II to SURF III and reinstalled several beam lines. Key operations are back online, and daily service to internal and external customers has been resumed. The energy of the electron beam has been successfully increased from 284 to 331 MeV, and eventual operation at 405 MeV is anticipated. A primary goal of this upgrade is to

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

provide the world's leading standard of irradiance in the DUV and EUV regions of the spectrum, and this goal is being realized. Calibration and standards services are being provided using an array of beam lines: one is being used for the determination of reflectivities of multilayer optics and related investigations; another is supporting NASA programs in solar physics and EUV astronomy; a third is being used for the ultraviolet (UV) and EUV detector transfer standards program; and a fourth has been equipped with an EUV conversion microscope for EUV lithography mask inspection.

The unusual geometry of the SURF ring permits collection of data over a large solid angle, which could make the ring a highly competitive, if not world-leading, source of synchrotron infrared (IR) radiation. The group is urged to do nothing that would preclude such a development in the future. Long-term issues for the facility include boosting the customer base and renewing the staff. By customary metrics (e.g., numbers of users and publications), SURF is already among the most cost-effective synchrotron facilities in the United States. If the number of users can be brought up to full complement, SURF should move into the lead for cost-effectiveness.

The Electron Physics Group is a world leader in the fabrication and analysis of small structures, particularly those involving thin magnetic layers. Polarized neutron reflectivity and scanning electron microscopy with polarization analysis (SEMPA) were used to reveal magnetic domain structures and layer-by-layer alignment of magnetization responsible for giant magnetoresistance (GMR) in cobalt-copper (Co-Cu) multilayers. A scanning tunneling microscope (STM) was used to study manganese (Mn) growth on iron Fe(001), with implications for models of biquadratic coupling in Fe-Mn-Fe(001) from SEMPA data. A magneto-optical trap was demonstrated for chromium, as a first step for possible creation of a monochromatic, coherent source of Cr atoms for novel deposition studies. Theoretical models were developed for spin-polarized light emission in scanning tunneling microscopy for the temperature dependence of exchange bias effects, for magnetic hysteresis in ultrathin films, and for electrical conductivity of GMR in thin film systems to test the validity of the relaxation time approximation.

The group has recently decommissioned its two older SEMPA instruments and is eagerly awaiting the arrival of a new field emission scanning electron microscope, which will be combined with its best, NIST-built, electron spin polarization analyzers. The resulting new SEMPA instrument will permit sub-10-nm resolution with improved spin analyzer sensitivity and instrument reliability.

The group has completed assembly of the new Nanoscale Physics Facility. This facility is centered on the measurement capability of a cryogenic, ultrahigh-vacuum STM that will operate at temperatures as low as 2 K with the ability to apply magnetic fields of varying orientation up to 1.5 T, or a fixed orientation field up to 10 T. The facility has two molecular beam epitaxy chambers, one for metal deposition and one for semiconductor III-V materials deposition, with in situ transfer of fabricated samples among the chambers. The facility will be used to probe the underlying physics in quantum confined structures on the nanometer-length scale. Software has already been developed to perform the atom-by-atom assembly of desired, complex nanostructures under completely autonomous computer control. The first experimental results from this facility are expected shortly.

Impact of Programs

The overall program of the Electron and Optical Physics Division is responsive to industry needs in high-density magnetic storage and devices, higher-density circuitry for electronic devices, and enhanced accuracy and accessibility of optical and radiometric metrology. All three groups within the division are in very strong positions to contribute to the National Nanotechnology Initiative proposed in the Administration's fiscal year 2001 budget. The work of the Electron Physics Group in characterization of

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

TABLE 5.2 Sources of Funding for the Electron and Optical Physics Division (in millions of dollars), FY 1997 to FY 2000

Source of Funding

Fiscal Year

1997 (actual)

Fiscal Year

1998 (actual)

Fiscal Year

1999 (actual)

Fiscal Year

2000 (estimated)

NIST-STRS, excluding Competence

4.7

4.6

5.0

5.4

ATP

0.1

0.2

0.2

0.1

OA/NFG/CRADA

0.8

0.5

0.6

0.7

Other Reimbursable

0.1

0.1

0.1

0.1

Total

5.7

5.4

5.9

6.3

Full-time permanent staff (total)a

27

27

23

23

NOTE: Sources of funding are as described in the note accompanying Table 5.1.

a The number of full-time permanent staff is as of January of that fiscal year.

magnetic thin films and fabrication of nanometer-scale structures is extremely important to U.S. industry in magnetic storage technology and next-generation integrated circuit manufacturing and is also completely in accordance with the division, laboratory, and NIST missions. Industrial collaborations in this area were noted in the technical merit section above. In view of the strong candidacy of EUV lithography as a likely successor technology in the manufacture of microelectronics, there is no doubt that the activities of the Photon Physics Group and SURF III and its calibration and standards capabilities constitute a key part of the national capability.

Division Resources

Funding sources for the Electron and Optical Physics Division are shown in Table 5.2. As of January 2000, staffing for the Electron and Optical Physics Division included 23 full-time permanent positions, of which 20 were for technical professionals. There were also three nonpermanent and supplemental personnel, such as postdoctoral research associates and part-time workers.

The staff characterizes repairs to the Radiation Physics Building as adequate. The procurement process was criticized as being inflexible, with the $2,500 threshold for competitive bidding thought to be too low. In light of the large recent capital investment in equipment, the panel's concerns about the funding now shift to providing adequate resources for the proper operation and staffing of the facilities.

Atomic Physics Division
Division Mission

According to division documentation, the mission of the Atomic Physics Division is to carry out a broad range of experimental and theoretical research in atomic physics in support of emerging technologies, industrial needs, and national science programs.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×
Technical Merit and Appropriateness of Work

The Atomic Physics Division is organized into five groups: Atomic Spectroscopy, Quantum Processes, Plasma Radiation, Laser Cooling and Trapping, and Quantum Metrology. The division is the nation' s premier source for atomic data such as atomic energy levels, transition probabilities, and transition wavelengths. This work is primarily carried out by the Atomic Spectroscopy Group. The Atomic Data Center achieved a major milestone in the past year with the inauguration of its second-generation, more sophisticated, Web-based data archive. Additional improvements have already been incorporated into the Web site since its introduction in direct response to customer feedback. This high degree of responsiveness is applauded by the panel. This Web site has approximately 150,000 hits per month from commercial, academic, government, and international users. The division also completed the first major revision in 13 years of the compilation of fundamental constants. The new compilation is now Web-based and receives approximately 150,000 requests per month.

Another major achievement of the Atomic Spectroscopy Group during the past year is the first accurate measurement of the spectrum and wavelengths of the components of the 157-nm laser transition of molecular fluorine. Last year the group obtained the first accurate measurement of the index of refraction of calcium fluoride at this wavelength. Accurate knowledge of these parameters is essential to the photolithography technology for the next generation of densely packed large-scale integrated devices. There is little doubt that this work will contribute significantly to the future profitability of the U.S. microchip industry.

Very important theoretical work in atomic and molecular physics is continuing in the Quantum Processes Group. A new initiative is under way to calculate the next generation of relativistic wave functions using nonorthogonal orbitals for use in ab initio computation of atomic structure. This is in response to the identification of a major source of systematic error in the current single and multi-configuration Dirac-Fock codes—the inadvertent mixing of Russell-Saunders coupling (LS) and jj (electron angular momentum) coupling. Another noteworthy theoretical achievement is the development of a simple algorithm to calculate the electron collision ionization cross sections for a wide array of molecules. The algorithm reproduces experimental cross sections to better than 20 percent for all molecules for which experimental values exist. This will be a very useful and widely applicable tool that provides a simple means of disseminating NIST expertise to applications such as atmospheric science or low-temperature processing of plasmas.

The launch of NASA's Chandra X-ray Observatory during the past year raises both an important challenge and an opportunity for NIST. Astrophysicists acquiring medium-energy x-ray spectra with Chandra are faced with a lack of accurate atomic data for high-ionization stages of many elements. These data are needed for the theoretical modeling of the cosmic phenomena being observed, which was unknown before the launch but is immediately evident from the observations. Astrophysicists now face the prospect of trying to extract science from these very valuable data with an inadequate set of basic atomic data. An analogous situation was faced in 1990 by ultraviolet spectroscopists contemplating the millions of UV transitions of low ionization stages across the periodic table, as the Hubble Space Telescope (HST) and its high-resolution ultraviolet spectrograph were being launched. In the 1990s, NIST atomic spectroscopists joined with others around the world to dramatically upgrade the atomic database needed to interpret the HST observations. The nation has invested billions of dollars in these space missions to acquire astrophysical data of high precision. The Physics Laboratory has the facilities and expertise to make a great contribution to solving this problem via x-ray spectroscopy and its electron beam ion trap (EBIT), which can form an excellent analogue of conditions inside an expanding supernova remnant. Since Chandra has a lifetime of 5 to 10 years and is in too high an orbit for maintenance

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

by a space shuttle, new data are needed quickly. The Quantum Metrology Group has taken up this challenge with enthusiasm, and the panel welcomes this move. The panel also encourages NIST staff to initiate collaborations with the community of astrophysicists using Chandra.

The Quantum Metrology Group has also begun an important collaboration with the National Institutes of Health and the Research Collaboratory for Structural Bioinformatics, the group responsible for the Protein Data Bank, to design methods for rapidly identifying protein fragments through x-ray powder diffraction. This effort combines simulating patterns directly from the database and a rapid means of data acquisition.

The division is also participating in an interlaboratory Competence project in length metrology. Progress on this project has been excellent. The division has constructed a laser system for displacement metrology in which the absolute accuracy of an iodine-stabilized laser is transferred to a bank of “flywheel” lasers with higher power and greater short-term stability. The flywheel lasers then exhibit the accuracy of the iodine-stabilized laser over both short and long timescales, an important achievement crucial to achieving real-time interferometric measurements for active servo control. The division has also designed and built a facility for prototyping interferometers. A two-stage passive vibration isolation system in conjunction with a specially designed vacuum chamber provides vibration isolation superior to any other system in use at NIST.

The Laser Cooling and Trapping Group continues to be a world leader, mostly owing to its forefront work with Bose-Einstein condensates (BECs). In the past year the group has made two significant advances. The first is the development of a Raman technique for ejecting coherent beams of atoms from BECs, one that offers a substantial advantage over previous approaches to such an “atom laser,” all of which relied on gravity to accelerate the atom beam. In the NIST system the atoms are ejected with a high enough velocity that the resulting beam does not spread due to interatomic forces. The second advance is the characterization and control of the quantum phase of the BEC. NIST researchers have measured the spatial variation of the quantum phase and shown that its uniformity is destroyed by releasing the condensate, because the interatomic interactions are converted to kinetic energy. They have also demonstrated their ability to write a phase variation on the condensate and have used this to do several fascinating experiments. The most spectacular is writing the phase variation onto the condensate so as to create a soliton, a solitary wave that propagates in a nonlinear medium at a speed slower than the speed of sound. The condensate is a nonlinear medium due to the interactions between its atoms. The experiments to characterize the phase of the condensate and modify it represent an example of the collaborative efforts of the Laser Cooling and Trapping Group and the BEC Theory Program in the Electron and Optical Physics Division. In fact, the cooperation between these groups is quite broad. They have worked together on several important aspects of laser cooling, such as the effects of scattering resonances and photoassociation spectroscopy. This true collaboration has made NIST one of the world centers for both experimental and theoretical cold atom research.

The experimental activities of the Plasma Radiation Group span an enormous range, from studies of the low-temperature plasmas used commercially to manufacture semiconductor devices to studies of the properties of highly charged ions relevant to fusion or astrophysical plasmas. Using the EBIT, one of few such apparatuses in the world, the group has been exploring the use of highly charged ions for lithography. Conventional ion beam etching relies on the kinetic energy of the ions. A highly charged ion beam can provide not only the kinetic energy but also the coulomb energy that is released when the highly charged ions capture electrons from the substrate. The effects of the highly charged ion beam are localized at or near the surface of the substrate, and to ensure that it is not examining the effects of exposure to the atmosphere subsequent to exposure to the ion beam, the group has recently incorporated a high-vacuum STM into its target chamber. This allows in situ analysis of samples subsequent to ion

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

bombardment. Recently the group observed the effect of bombarding graphite surfaces with Xe44+ ions. Protrusions rather than craters occur where the ions hit the surface. These results indicate that the highly stripped ions have penetrated below the surface of the graphite and removed electrons from nearby carbon atoms, creating a coulomb explosion of the resulting carbon ions, which pushes up the surface of the graphite.

Impact of Programs

Interactions between atoms now limit the cesium fountain as a time standard. Further improvement of the time standard requires a better understanding of how dense samples of cold atoms behave. It is impossible to foresee all of the phenomena that will affect an improved time standard, so in the long run the most efficient approach is to study cold atoms in a broad way. NIST is doing precisely this in its ongoing research on a cesium atomic fountain frequency standard, Bose-Einstein condensation, photo-association spectroscopy, and ultracold plasmas.

The future potential for quantum computing using condensate atoms in an optical lattice poses many challenges and is most exciting because it may offer the possibility of many qubits of computing power. The Laser Cooling and Trapping Group is actively pursuing these possibilities, in parallel with the ion trap effort of the Time and Frequency Group.

The impact of the new program on rapid protein identification will be primarily in drug design and medical diagnosis. This is an example of fruitful interlaboratory cooperation.

The long-standing program on x-ray metrology for the semiconductor industry is now making an impact, with the realization that such methods are needed for the generation of very thin films such as high-permitivity gate dielectrics. Physics Laboratory expertise will be used in the coming year to prepare and calibrate new Standard Reference Materials for the semiconductor industry, in collaboration with the Materials Science and Engineering Laboratory.

The impact of the newly revised fundamental constants appears to be strong. The fundamental constants database is accessed about 250,000 times a month, and the more specialized atomic spectroscopy database is accessed 150,000 times per month. About a third of these requests are from U.S. industry, showing that NIST is fulfilling its role of disseminating its information to this major stakeholder. The ability of NIST to contribute to the interpretation and utilization of data from the Chandra will also have a major impact on the U.S. astrophysics program.

Division Resources

Funding sources for the Atomic Physics Division are shown in Table 5.3. As of January 2000, staffing for the Atomic Physics Division included 31 full-time permanent positions, of which 26 were for technical professionals. There were also 14 nonpermanent and supplemental personnel, such as postdoctoral research associates and part-time workers.

The panel is extremely pleased to note that the PL management has made a strong commitment to the future of atomic spectroscopy. The Atomic Spectroscopy Group within NIST's Physics Laboratory remains the preeminent organization in the world for the acquisition, systematic evaluation, and archiving of fundamental atomic data. Many commercial, academic, and government organizations depend on this group as the primary source of comprehensive and accurate atomic data—wavelengths, atomic energy levels, transition probabilities, line-broadening parameters, hyperfine structure, isotopic shifts, and other data. In last year 's report the panel expressed considerable alarm that this group was on a

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

TABLE 5.3 Sources of Funding for the Atomic Physics Division (in millions of dollars), FY 1997 to FY 2000

Source of Funding

Fiscal Year

1997 (actual)

Fiscal Year

1998 (actual)

Fiscal Year

1999 (actual)

Fiscal Year

2000 (estimated)

NIST-STRS, excluding Competence

4.7

5.7

6.7

6.6

Competence

1.1

0.7

0.3

0.3

ATP

0.2

0.2

0.2

0.2

OA/NFG/CRADA

1.2

1.2

0.8

1.4

Other Reimbursable

0.2

0.2

0.2

0.2

Total

7.4

8.0

8.2

8.7

Full-time permanent staff (total)a

31

30

32

31

NOTE: Sources of funding are as described in the note accompanying Table 5.1.

a The number of full-time permanent staff is as of January of that fiscal year.

course toward disintegration. Many of its key personnel, including the group leader, were retiring. It was unclear whether NIST had the will to maintain this very important, though unglamorous, function.

Funding from the PL Director's Reserve has been applied to the rejuvenation of the Atomic Spectroscopy Group. The group is now larger by virtue of combining staff formerly dispersed among several different groups within the organization. It has a full-time leader, and new employees are being recruited. Postdoctoral fellows, guest researchers, and contractors are an invaluable supplement to the core staff. Funding support from the Director' s Reserve has a finite lifetime, dropping to zero after 7 years. By that time the Atomic Spectroscopy Group is expected to be self-sufficient. The panel believes it is very important that management follow these very constructive steps with a further commitment to support the Atomic Spectroscopy Group in identifying new sources of external funding. The atomic spectroscopists and data archivists have achieved an impressive record of providing data of great value to other organizations. However, there is a disproportionately small return of value and support to the group, particularly from industry, whose future profits may rely heavily on the data acquired by NIST. A major initiative by management to market the capabilities of this group would be very helpful in opening doors to new funding sources and better prospects for its long-term financial health.

In 1999, the panel expressed concern about the continuity of expertise in groups in the division and recruitment of staff to maintain and develop the major research thrusts. The panel is very pleased to report that this issue has been squarely addressed by Physics Laboratory management, and appropriate plans to deal with these concerns are well advanced.

Optical Technology Division
Division Mission

According to division documentation, the mission of the Optical Technology Division is to provide high-quality national measurement standards and support services to advance the use and application of optical technologies, spanning the ultraviolet through microwave spectral regions, by diverse customers in industry, government, and academia.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

The division mission statement, deriving clearly and faithfully from the PL mission, encompasses an extremely broad range of technical responsibility. The panel is impressed by the ability of the division to respond so fully to this extensive mission. It is clear to the panel that the division recognizes that basic, long-term theoretical and experimental research in optical and photochemical properties of materials, in radiometric and spectroscopic techniques and instrumentation, and in application of optical technologies is required to accomplish its mission. The division is conducting an effective, focused program of research to these ends.

The Optical Technology Division has used an inclusive, strategic planning approach to formalize and document its concepts for the direction and choice of the division's programs since 1997. This approach is also used to develop group and individual staff member plans. Placing group and individual plans in the context of the division 's strategic plan reinforces the relevance of these programs for division staff and enables them to emphasize the relevance of their plans to customers, collaborators, and others. Although this process is formally undertaken annually, division management stresses that the strategic plan is dynamic and is, in fact, an implicit part of every technical discussion and potentially modified by these discussions.

Technical Merit and Appropriateness of Work

The Optical Technology Division has the institutional responsibility for maintaining two base SI (International System of Units) units: the unit of temperature in the range above 1234.96 K and the unit of luminous intensity, the candela. The division maintains the national scales for other optical radiation measurements and ensures their relationship to the SI units. These measurement responsibilities include derived photometric and radiometric units, the radiation temperature scale, spectral source and detector scales, and optical properties of materials such as reflectance and transmittance. Industries that rely on the division's services include the aerospace, biotechnology, photographic, lighting, display, automotive, pharmaceutical, semiconductor, and scientific instrumentation industries. The division also provides measurement support for national needs in solar and environmental monitoring, health and safety concerns, and the defense industry. It has the responsibility to provide measurement support services to other government agencies for the efficient and effective pursuit of their missions.

The division has active research programs to develop optical and spectroscopic tools to gather previously unattainable information on industrial, biological, and environmental processes. Tunable, ultrafast IR, visible, and ultraviolet laser methods are used or are being developed to identify transient species, molecular complexes, and other chemical species in both homogeneous and inhomogeneous environments (e.g., material interfaces). Programs have been very effectively planned to share benefits from advances occurring throughout the division. Examples include the combined use of SURF III, the high-accuracy cryogenic radiometer (HACR), and the Spectral Irradiance and Radiance Calibration with Uniform Sources (SIRCUS) Facility to provide improved optical radiation scales, as well as the development of transfer electrical substitution radiometers for the Medium Background Facility. The division plans and fosters such cross-functional, intergroup synergy. This translates into direct and significant advantage to the division's customers. The panel commends the division's productive leveraging of its resources and accomplishments.

The Optical Temperature and Source Group maintains the national scales for radiometric measurements of sources; the international scale for temperatures above the freezing point of silver; and reference instruments for ultraviolet, visible (VIS), and near-infrared (NIR) spectrophotometry. Calibration facilities include the Facility for Automatic Spectroradiometric Calibration, the Facility for Advanced

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

Radiometric Calibration, radiation thermometry facilities, the Spectral Tri-function Automatic Reference Reflectometer (STARR), and aperture area measurement facilities.

STARR currently supports SRMs for specular reflectance, diffuse reflectance, and reflectance factor measurements as a function of wavelength. The technical knowledge developed with the design and operation of STARR enabled the developments currently under way as part of the Color and Appearance project, which began approximately 2.5 years ago as a result of interest from the paint and textile industries. The division has built a new gloss and haze instrument, designed a state-of-the-art colorimeter, and performed comparisons with the National Research Council of Canada on gloss standards and with the Physikalisch-Technische Bundesanstalt on reflectance. Work is under way to assemble a reference instrument for measuring the 45°/0° reflected color of a material. The Color and Appearance project is a collaborative effort by this division, the NIST Building and Fire Research Laboratory, the NIST Manufacturing Engineering Laboratory, and the NIST Information Technology Laboratory.

Refinements to the Facility for Advanced Radiometric Calibrations (FARCAL) are extending the usefulness of this facility to more metrological problems. This is a direct result of the original design-for-flexibility approach taken for its medium background chamber (MBC). For example, the use of the MBC in characterization of the thermal-infrared transfer radiometer (TXR) resulted in the TXR's being placed on the detector-based scale. This is significant because it compares the NIST water bath blackbody with the detector scale.

The Facility for Automatic Spectroradiometric Calibrations (FASCAL) provides the basis for spectral irradiance and radiance measurements for U.S. industry, the scientific community, and the military. The panel noted in its previous report that this facility was in desperate need of upgrading. A new FASCAL has been designed that will use absolute detectors as the basis of the spectral irradiance and radiance scales. The detectors have been constructed, and a new transfer monochromator system and optical bench are being implemented. The quality of the calibrations and throughput for irradiance and radiance measurements should be markedly improved when the new FASCAL is operational. The resulting improved quality of calibration and improved throughput are of direct and significant benefit to users of this facility. Completion of the improved FASCAL will bring the nation's spectral irradiance and radiance measurement capability to a level that will redefine world-class capability. The Optical Temperature and Source Group is commended for the recent commitment of additional personnel to the FASCAL upgrade project.

High-accuracy aperture measurements continue to be an important enabling technology. As the division transfers the maintenance of optical radiation scales to detectors, the requirement for accurately determined apertures becomes more pervasive. The effort expended in the division 's pilot laboratory for international intercomparison of aperture measurement will result in further improvement in international agreement on optical radiation scales.

Measurement of retroreflectance, which is important to the nighttime visibility of highway signage and markers, has been pursued by this group. The group has sought funding from external sources without success. This is unfortunate in light of the importance of this type of measurement and the unique ability of NIST to contribute to improvement of the metrology of retroreflection. The panel recommends that NIST consider directly funding this activity.

The Rapid Thermal Processing (RTP) project is an industry-driven measurement effort that is indicative of the division's responsiveness to critical measurement needs in rapidly developing industries. The RTP project goal is to measure the temperature of production silicon wafers, using a noncontact process control technique, to within ±2 °C. This has required the development of improved thermocouples for evaluation and verification of the radiation thermometry measurement method. The

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

feasibility of this method was demonstrated this year. At an RTP workshop held in 1999 and the 8th International Conference on Advanced Thermal Processing of Semiconductors (to be held in Gaithersburg in September 2000), the Optical Temperature and Source Group is proactively disseminating this measurement technology to the semiconductor industry. These efforts have helped the industry to realize the technological impact and potential economic advantages of noncontact temperature measurement as a process control tool. The group has a project under way for the noncontact measurement of chips from machining operations. This work indicates that the conventional assessment of machine tool operation and the conventional responses to achieve optimization may not in fact lead to optimal performance. This activity has practical application in the optimization of machining rates and the understanding of tool-life parameters. The effort is producing practical data of use to and of significant economic value for U.S. industry.

The Optical Properties and IR Technology Group establishes and disseminates primary standards for transmittance and reflectance measurements in the IR. It also studies the optical properties of materials from the microwave to the UV and develops theoretical models to interpret these behaviors for further standards development. Its principal facilities include the low-background IR (LBIR) calibration facility, with which several sensitive NIST transfer standards detectors have recently been developed. The group also is developing superconducting materials for optical sensor applications. The group's core metrology programs target the areas of absolute radiometers, infrared technology, and IR optical properties of materials. The group is responsible for establishing, improving, and maintaining the U.S. primary standard for LBIR measurements. The group conducts basic and applied research in each of these areas in collaboration with academia and other divisions at NIST.

The group was commended in the last review on its forward thinking in developing expertise and technology with potential biological applications. At the time of this review, a major fiscal year 2001 budget initiative proposed to Congress by the Administration is in nanotechnology. Since the properties of both nanostructures and biological constructs may be different from those of conventional bulk materials, a uniform measurement and standards system is required for these emerging areas of the U.S. economy. The Optical Properties and IR Technology Group should work aggressively with U.S. industry and universities to develop a measurement infrastructure in support of these areas.

The Optical Properties and IR Technology Group is developing state-of-the-art equipment and techniques for critical measurements over a wide range of applications. Raman spectroscopy is used for measuring and characterizing nanostructures and biological materials. In combination with the 7-T magnet, magneto-Raman spectroscopy can be used to see effects on biological materials and systems. The NIST advanced radiometer (NISTAR) will be used to measure total absolute solar irradiance and total Earth reflected and emitted light viewed from the L1 point in space. The National Research Council's Space Studies Board and external experts from NASA validated the design and performance of this instrument, which was designed, built, and tested within a year using external funds from NASA. The NISTAR program represents not only a major technical success but also an appropriate application of NIST capabilities to the needs of the space community. The design and fabrication of a transfer radiometer for a Department of Defense (DOD) space sensor chamber have also been completed. A next-generation hyperspectral radiometer is being discussed with industrial and DOD users and stakeholders. These accomplishments are appropriate to the NIST mission and are of great significance to U.S. interests. Another major accomplishment of the group was the calibration of two blocked impurity band detectors that will be used as ultralow-noise, high-spatial-uniformity transfer standard detectors to cover the 2- to 28-mm spectral region.

The Optical Sensor Group establishes the national measurement scale for the candela, a fundamental SI unit. The group's principal facilities include the high-accuracy cryogenic radiometer (HACR), the

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

detector Spectral Comparator Facility, spectral irradiance and radiance calibration with uniform sources (SIRCUS), and the SURF III radiometric facility. The group also provides calibration services for optical detectors for the spectral region from 200 nm through the IR.

The HACR currently remains the basis for the national standard for optical power measurements. HACR is the foundation of the nation 's radiometric measurement chain and is used to maintain the scales of spectral radiance, spectral irradiance, and absolute detector responsivity from 200 nm to the far IR. The group is currently constructing a second-generation instrument (HACR 2) that will become operational within the next 2 years. The HACR 2 design will increase the dynamic range of power measurement to a range of 1 mW to 70 mW; reduce the uncertainty compared with HACR; improve response time by nearly an order of magnitude, which will enable more direct comparisons to be made to HACR 2 than are now possible with HACR; relax restrictions on the size of detectors that can be directly compared on HACR; and allow for cavity replacement as technology evolves. In its last review, the panel commended the division for placing HACR 2 in the laboratory where SIRCUS is located. SIRCUS is now being used for calibrations in the UV/VIS/NIR. The IR SIRCUS is being constructed. Plans to combine the use of HACR 2 and SIRCUS, which will provide a more direct measurement of spectral radiant power and an improved accuracy of radiometric and photometric units, are again strongly endorsed by the panel.

The group is building new spectroradiometric facilities at SURF III to extend measurement capabilities in the UV and the IR. This effort will establish SURF III as an absolute source of synchrotron radiation. Work has been completed on the beam line for detector calibration and optical damage characterization. Design work is complete, and construction has begun for the current monitor and the white light beam for another beam line.

The evaluation of optical damage to detectors for the wavelengths of interest in developing semiconductor lithography—193, 157, and 13 nm—is timely. The purpose of this work is to identify stable detectors to accurately and reliably calibrate exposures in the semiconductor manufacturing process. An objective is to develop durable, accurate, low-profile sensors for this market area. Considerable work is needed in this area to establish NIST-traceable metrology and to assist industry in developing protocols for accurate dosimetry in the high-intensity UV area. Synchrotron light, as well as UV excimer laser light at 193 nm, has been used to characterize the damage characteristics of photodiodes used for irradiance measurements at the focal plane of a semiconductor photolithography stepper. Further work will investigate damage characteristics at shorter wavelengths (157 and 13 nm). Work to date has produced two new bases for UV-sensing devices based on nitrided silicon and platinum-silicon that endure high-intensity exposure over extended periods of time.

The metrology of colorimetry of cathode-ray tube (CRT) displays and the development of a matrix algorithm to improve the performance of colorimeters for CRT monitor color evaluation have been fully implemented. Efforts in this area are supported by Calibration Coordination Group funding from the Air Force, as well as by Advanced Technology Program (ATP) funds. The future direction of this effort will be to apply this methodology to the measurement of other important radiant sources such as light-emitting diodes (LEDs).

The Optical Sensor Group has collaborated with researchers in the Atomic Physics Division to make ultraprecise measurements of the index of refraction of quartz and calcium fluoride for the semiconductor industry. Precise knowledge of the optical characteristics of UV-transmitting materials is crucial to the design of optical systems for patterning semiconductor wafers. As linewidths in the semiconductor industry decrease, fabrication processes are forced to move to shorter-exposure wavelengths to maintain line definition. Thus, accurate characterization of optical materials is critical if the U.S. semiconductor industry is to maintain its worldwide leadership position. The group is also developing and characteriz

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

ing new optical detectors and detector filter packages to meet the needs of industrial, environmental, defense, and space applications. Detectors using tunnel trap techniques are being developed with large fields of view and large beam sizes. New detectors based on indium antimonide (InSb), mercury-cadmium telluride, and pyroelectric techniques are under development for the IR.

Work on characterizing the measurement of total luminous flux is very significant for the photometric measurement community in the United States and internationally. These investigations provide clear guidance for the proper application and use of integrating spheres in photometry and radiometry. The Optical Sensor Group seeks to improve uncertainty and reduce calibration chains by intercomparison between methods of realization of a particular quantity. This effort is strongly supported by the panel, because multiple approaches to the realization of these important bases of measurements for U.S. industry clearly improve their reliability and increase their value to U.S. industry and others.

The Laser Applications Group develops and applies state-of-the-art laser diagnostics for applications in industrial and environmental processes; uses tunable, ultrafast IR, visible, and UV lasers to identify transient chemical species involved in molecular reactions in liquids and at semiconductor, metal, polymer, and biological surfaces; and probes the performance of semiconductor interfaces related to device fabrication, reliability, and function of semiconductor devices and biological and chemical sensors; and measures nanometer-scale structures and single molecules using optical methods. Its principal facilities include a laser-based bidirectional reflectance distribution function instrument; several ultrafast laser systems, including a new terahertz spectrometer; two near-field scanning optical microscopes (NSOMs), one dedicated to wet biological or chemical samples; and two confocal microscopes for single molecule manipulation and screening.

Last year, the group was commended for significant programmatic decisions. The group terminated some other excellent activities in order to focus on surfaces and interfaces related to semiconductors, biotechnology, and optoelectronics. The group obtained NIST Competence funding for advanced terahertz applications and ATP funding for DNA diagnostics, catalysis, tissue engineering, and organic electronics and imaging for combi-screening. Terahertz laser technology is being used for imaging and applications to DNA, DNA chip technology, and protein folding in real time. The panel again commends this group for the ability to refocus its efforts on the science and methodologies with the greatest impact in critical areas of emerging technologies.

The group is applying vibrationally resolved sum-frequency generation with broad-bandwidth IR pulses to study the absolute orientation and kinetics of hybrid bilayer membranes. The ability to monitor the formation of these membranes can provide information on many cell-level biological functions. A range of potential commercial applications could foreseeably arise from this area, such as drug response monitoring and tissue engineering.

Near-field scanning optical microscopy (NSOM) and confocal microscopy methods are being developed to extend the measurements and standards infrastructure to nanoscale optical characterization of thin films and interfaces. Techniques include wet-cell NSOM suitable for investigating biological or biomimetic films, a near-field probe preparation and evaluation facility, and a confocal scanning microscope for single-molecule imaging and spectroscopy. An important aspect of this work is demonstration of the applicability of these techniques to new problems, such as mapping the topography and fluorescence of polymer mixtures, which cannot be adequately addressed by other established methods. The development of polarization modulation confocal fluorescence microscopy as a tool for biological investigations, e.g., for antibody rearrangement at cell surfaces, uses single-molecule rotational dynamics as a probe of biomolecule conformation.

The Spectroscopic Applications Group develops and applies advanced spectroscopic instrumentation and theories to solve fundamental problems in physics, chemistry, and the engineering sciences. It

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

provides industry and the scientific community with improved spectroscopic instrumentation and measurement methods; standard reference frequencies, data, and databases; and theoretical models for determining the fundamental properties, energetics, and internal dynamics of stable molecules, molecular complexes, and reactive species such as radicals and ions. Activities are focused on emerging technologies in the microwave, IR, and UV spectral regions. Principal facilities include a pulsed molecular beam Fourier transform microwave (FTMW) instrument, an IR cavity ring-down spectrometer (CRDS), Fourier transform IR (FTIR) instruments, and a new high-resolution UV-VIS spectroscopy facility.

Terahertz spectroscopy is being applied to model biomolecules. This effort will provide the spectroscopic data required to validate and guide the computational simulations of biological molecules. The FTIR is being applied to the characterization of continuum absorption by oxygen in the atmosphere. This process contributes more to atmospheric absorption of heat than do the anthropogenic gases but is only partially included in current models. A recent application of FTMW to simulated automobile exhaust characterization in collaboration with the Analytical Chemistry Division of CSTL is indicative of the group's commitment to demonstrating applications for its techniques with short transition times to practical industrial use. Broader application to the spectroscopy and dynamics of combustion, plasmas, detonation, and propulsion are tactical goals for the group.

Progress has been made on the development of molecular databases, and several databases are available on the Internet. The group's effort to develop a center that would critically evaluate the entire world's output of high-resolution spectral data for different classes of molecules in different spectral regions remains unfunded.

Impact of Programs

In general, the efforts of the Optical Technology Division address the needs of U.S. industry and the U.S. scientific community. In the opinion of the panel, the division's present efforts will keep the United States at the state of the art in the areas of measurement and research within its scope.

Some examples of impact or potential impact are given here. Worthy of special note are the Rapid Thermal Processing project and the Color and Appearance Competence project, both of which respond directly to the needs of U.S. industry and have evolved from ongoing interactions with broad cross sections of the respective industries. Rebuilding of the HACR 2 facility and the program to combine its use with the SIRCUS facility and SURF III are good examples of the continuing development of state-of-the-art equipment for critical measurements. The project to apply noncontact thermometry measurement to machining chips is an example of how a supposedly low-technology problem can in fact be complex and how techniques leading to economic and competitive advantages can be produced by exceptional metrology. The effort to shorten the calibration chain for radiation temperature measurements will result in simpler and more accurate techniques and will significantly advance the state of the art in temperature measurement. Radiometric calibrations for NASA's Earth Observing System and for DOD space-based activities from FARCAL provide important data for characterizing Earth's environment and its evolution, as well as critical national defense information.

Worldwide, more than $2 billion worth of high-intensity industrial UV processing units have been installed in converting and printing operations, with 40 percent of this fast-growing market in the United States and Canada. High-intensity UV light is used to change nonvolatile liquid inks and coatings to cured or dried surfaces in a myriad of applications, such as the glossy covers of magazines, coatings on fiber optics, and wood finishes, imparting considerable value-added to such products. This technology enables manufacturers of coated products to virtually eliminate emissions of volatile organic com

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

pounds from their processes. Determining the UV damage characteristics of detectors and the index of refraction of UV-transmitting materials plays an important and critical role for the U.S. semiconductor industry. In July 1999, a well-attended (60 participants) UV Metrology Workshop was held at NIST. Subsequently, NIST personnel participated in meetings of the UV Measurements Focus Group of the industrial association RadTech International North America. Continued interaction is planned, with the possibility of RadTech undertaking a CRADA with NIST in this area. These activities represent an excellent example of cooperation between NIST laboratories and an important U.S. industrial segment. The division is to be commended for its efforts in this regard.

Activities in colorimetry will have immediate and substantial value to industry. For example, accurate calibration of computer monitors is of value as commerce moves to the Internet. Increasingly, industry will make production decisions and consumers will make purchasing decisions based on colors viewed on computer monitors. The costs of color selection errors due to inaccurately portrayed colors can be substantial. Standards and techniques for calibrating monitors are gaining increasing economic importance. The increased use of LEDs in applications ranging from simple indicator lamps, to automotive taillights, to traffic lights and streetlights places similar economic importance on characterization and standardization of the characteristics of LED optical emission.

The production of Standard Reference Materials (SRMs) is an important service offered by the division. The SRMs produced include standard lamps and specular and diffuse reflectance artifacts. The division also has the capability to make gloss measurements in accordance with the American Society for Testing and Materials (ASTM) D253 and the International Organization for Standardization (ISO) 2813 standards. Shortly, the ability to make reflective colorimetry and haze measurements will add additional SRM capability.

International key intercomparisons are critical to gathering the information needed to advise U.S. industry on metrology issues worldwide, to provide technical guidance on international memoranda of understanding affecting the U.S. economy, and to advance metrology within the division. The division is involved in several international key intercomparisons, including spectral irradiance, apertures, spectral transmittance, and 45∞/0∞ reflectance (sponsored by the Consultative Committee on Photometry and Radiometry) and intercomparison of correlated color temperature (sponsored by the European Union). The division is the pilot laboratory for the apertures and 45°/0° reflectance intercomparisons. The Optical Temperature and Source Group, in particular, is commended for incorporating the division's vision of world-class metrology, as shown in its recent results and as embodied in its current plans for new instrumentation and metrology.

Short courses and workshops offered or supported by the division are another effective means of transferring NIST results to customers. These courses include a radiation temperature short course, a photometry short course, and a workshop on the metrology and modeling of color and appearance. Participation of the group in key comparison activities plays an important role in maintaining product flow from U.S. industry to other nations around the world.

The division has established a consortium of NIST, industry, and universities to advance and transfer knowledge in measurement for the optical properties of materials. The consortium plans to make measurements and evaluations of optical materials and to make these available on the NIST Web site. The consortium consists of five industrial partners and several universities and has significant room for growth.

The division needs to dedicate resources and move quickly to provide effective technical leadership and critical measurement infrastructure for developing areas of national economic importance such as biotechnology and nanotechnology.

As the division develops national standards and measurement capabilities in any area, it is important

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

for a technical peer review group to be established to ensure that the highest-quality measurements and most effective services are provided to U.S. researchers, technology developers, and commercial entities. The panel reiterates this point, made in its previous report.

Division Resources

Funding sources for the Optical Technology Division are shown in Table 5.4. As of January 2000, staffing for the Optical Technology Division included 46 full-time permanent positions, of which 41 were for technical professionals. There were also 10 nonpermanent and supplemental personnel, such as postdoctoral research associates and part-time workers.

Overall, approximately 32 percent of the division's funding comes from other agencies and CRADAs. If Competence and ATP funding are included with this 32 percent, then the total division funding that comes from nonbase funding is approximately 50 percent. The Optical Properties and IR Technology Group operates on 70 percent customer funding. Only about 40 percent of the Optical Temperature and Source Group funding comes directly from NIST. Leaders of these groups spend as much as 30 percent of their time pursuing outside funding. For perspective, the Optical Technology Division percentage of nonbase funding—32 percent—places it seventh out of 37 divisions within NIST.

This situation is complex. External funding increases the division 's responsiveness to meeting needs that have demonstrated importance as measured by willingness to fund, and much of the other agency (OA) work is by its nature best performed by NIST. There is concern, however, that the division might focus on delivering results to OA and CRADA partners rather than on addressing priorities dictated by its mission. External funding also raises the possibility of competition with industry. However, external funding has a spinoff benefit to basic services in the form of technologies, methods, and instrumentation developed in externally funded projects. Although the panel is concerned about this situation, increasing base funding will not eliminate OA and other external funding or this issue. Division management has done exceptionally well in balancing these funding issues.

TABLE 5.4 Sources of Funding for the Optical Technology Division (in millions of dollars), FY 1997 to FY 2000

Source of Funding

Fiscal Year

1997 (actual)

Fiscal Year

1998 (actual)

Fiscal Year

1999 (actual)

Fiscal Year

2000 (estimated)

NIST-STRS, excluding Competence

5.4

5.3

5.5

5.6

Competence

0.6

0.6

1.0

0.8

ATP

0.3

1.0

1.0

1.4

Measurement Services (SRM production)

0.1

0.1

0.1

0.0

OA/NFG/CRADA

4.0

3.7

3.8

4.1

Other Reimbursable

0.5

0.5

0.7

0.6

Total

10.9

11.2

12.1

12.5

Full-time permanent staff (total)a

44

46

44

46

NOTE: Sources of funding are as described in the note accompanying Table 5.1.

a The number of full-time permanent staff is as of January of that fiscal year.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

The general impression of the panel is that the quality of the division 's scientific personnel is high. For example, one staff member won the Presidential Early Career Award in 1999, a reflection on the organization's excellence. The staff seem to be keeping current, and in certain groups, turnover is planned to be at least 15 percent, approximately that of industry. Actual turnover varies among groups, but all groups are encouraged to be aware of the need to upgrade staff skills and to develop strategies to accomplish this. The panel was impressed by the division's group leaders. They had genuine concern for their staff and took a great deal of pride in their accomplishments. Staff levels are relatively low for the type and quality of work performed. The diligence and dedication of the scientific personnel are remarkable and should be highly valued. For example, the difficulty of measuring aperture area to 0.003 percent is not readily apparent to anyone who has not undertaken the effort.

The panel would like to see the division develop succession plans for management positions. The combination of technical expertise, breadth of scientific knowledge, and institutional and personnel management skills required by a management position in the division requires cultivation of potential candidates well in advance of the need.

There do not appear to be any barriers to interlaboratory cooperation, as evidenced by the large numbers of collaborative projects noted. NIST apparently fosters a collegial environment where scientific interest leads to collaboration, which is sought out, supported, and encouraged by management at the group, division, and laboratory levels.

Division management sees involvement in international documentary standards organizations as fundamental to its role. All management levels believe these activities receive complete management support. Based on the membership and prominence of division personnel in a wide variety of standards organizations, advisory committees, and industry interest groups, the panel agrees that division management is supporting this activity with staff time at an appropriate level. Participating division personnel should work with U.S. industry representatives involved with specific international documentary standards organizations to elicit, in advance, the U.S. industry consensus on issues addressed by these organizations.

The division cooperates internationally on key intercomparisons. As the Bureau International des Poids et Mésures (BIPM) protocol for key intercomparisons is implemented, it is expected that the division will take a leading regional role through the North American Metrology Organization (NORAMET, a regional collaboration in national measurement standards and services), the Sistemo Interamericano Metrologia (SIM), or a subsequent regional organization. It is absolutely essential for U.S. industry that NIST be the first among nominal equals in any regional organization. This means that planning for resources must begin immediately. This effort should be coordinated with the NIST Office of Standards Services and other NIST divisions that have the authority to agree to technical understandings between the United States and other countries and regional groups.

Ionizing Radiation Division
Division Mission

According to division documentation, the mission of the Ionizing Radiation Division is to provide national leadership in promoting accurate, meaningful, and compatible measurements of ionizing radiation (x rays, gamma rays, electrons, neutrons, energetic charged particles, and radioactivity).

The Ionizing Radiation Division mission statement adequately embraces the overall goals and objectives of the division, and the division 's efforts are largely aligned with this statement.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

The Ionizing Radiation Division maintains a strong relationship with the scientific and industrial communities. The three groups in this division—the Radiation Interactions and Dosimetry Group, the Neutron Interactions and Dosimetry Group, and the Radioactivity Group—interact routinely with their constituent communities by participating in various associations and conducting focused workshops on key topics. The division has been responsive to national needs as defined by the Council on Ionizing Radiation Measurements and Standards (CIRMS), a coordinating council involving industry, government, and academic constituencies. The division routinely takes a leadership role in establishing appropriate metrology standards and identifying measurement procedures to ensure the highest level of metrology.

Technical Merit and Appropriateness of Work

The Radiation Interactions and Dosimetry Group has enhanced its abilities to develop computational methods and codes by adding a new scientist with expertise in theoretical and computational analyses appropriate to the maintenance of dosimetry databases in the atomic and nuclear areas. This could have a major impact on the division's international contributions, but long-term budgetary commitment is needed to keep very qualified personnel in this area. These activities intend to bring together theoretical modeling and empirical results. As medical applications in brachytherapy expand to include more β-emitters and soft x-ray or gamma-ray emitters, the need to model radiation transport at a submillimeter level greatly increases. The ability to access codes and atomic and nuclear databases on NIST's Web site is of great benefit to the academic and industrial communities. These databases and codes are important and useful to the dosimetry community. This effort is fundamental to keeping NIST at the forefront.

The expanding role of Web-delivered data is finally being addressed by the group. Recent inspection of its Web pages shows that they reflect this effort admirably. Although no data about the site's hit rate were supplied, anecdotal evidence from panel members suggests that these pages are having a positive impact on the dosimetry community. The group should summarize the activity on these pages and articulate a plan of expansion, needs assessment, and delivery for data delivery on the Web.

The development of a commercial source for alanine pellets and thin films, down to 10 mm, with the possibility of each strip being individually bar coded, will greatly facilitate the adoption of electron paramagnetic resonance (EPR)-based dosimetry. Major industrial users await the opportunity to collaborate with NIST in the launch of this methodology. Alanine dosimetry is critical to the emergence of applications such as food irradiation. The coordinated development of an Internet-and/or telecommunications-based data transmittal service by the Radiation Interactions and Dosimetry Group and the National Advanced Manufacturing Testbed in the Manufacturing Engineering Laboratory will lead to lower-cost direct NIST dosimetry calibrations. These alanine and EPR dosimetry methods are inherently less operator dependent than current film-based measurements that rely upon shifts in optical densities. This Internet- and telecommunications-based data and calibration system may, in the long term, diminish the demand for secondary standards laboratories.

Another highly visible dosimetry effort of this group involves brachytherapy source characterization. Over the last several years, NIST has mounted a comprehensive program with close ties to manufacturers. Virtually all North American and leading international manufacturers of brachytherapy sources are working closely with NIST. A comprehensive dosimetry effort is emerging, spanning source activity, distribution of absorbed dose in condensed matter, air kerma determinations, and β-source output. These programs are now the cornerstone of this application of radiation in medical

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

treatment. NIST might consider a sequence of seminal publications promoting this work to the user community and providing a comprehensive presentation of the science and techniques.

The Radiation Interactions and Dosimetry Group has developed a forensic technique using tooth enamel to determine radiation exposure. Since radionuclides from the blood can be fixed in the teeth, this EPR technique measures carbonate radicals created by the electron trapping that results from the effects of radiation. The half-lives of these systems are approximately a million years and, therefore, the EPR signal will be proportional to the accumulated dose. This technique has broad-reaching implications—in essence, each of us carries our own personal lifetime dosimeter—and could be a very important measure for determining the effects of long-term, very low dose rates on human health. The Department of Energy (DOE) has recognized the limitations of the present methodology of linear extrapolation of dose effect to zero amounts of radiation. DOE is studying the validity of linear extrapolation at near-zero radiation exposure, but measurements at such low levels of radiation are very difficult. The techniques being studied in the Radiation Interactions and Dosimetry Group could be of major value in these DOE studies. Contact with appropriate technical directors in the Environmental Management Science Program of DOE is strongly suggested. A broad-based radiation exposure data bank needs to be established in cooperation with the American Dental Association so that meaningful statistical correlations can be established with existing databases, such as those for cancer incidences. This effort can address societal concerns about radiation in general and its use in industrial processing, as well as document areas where radiation safety is needed. To support this work, the division needs to improve the sensitivity of its existing EPR equipment by acquiring equipment with enhanced microanalytical capabilities.

The ultracold neutron (UCN) source at the NIST Center for Neutron Research (NCNR) provides a world-class facility for the Neutron Interactions and Dosimetry Group and enables a variety of basic physics research and applications. An extraordinarily elegant, yet frustratingly subtle, experiment employed a neutron magnetic trap to demonstrate complete three-dimensional magnetic trapping of ultracold neutrons. Using liquid helium (He) as a cooling agent, cold neutrons are trapped in a magnetic bottle. After filling, neutron β-decays are measured using helium as a scintillation agent for the recoil proton energy losses. Various experimental obstacles, including contamination and background signal, obscured the β-decay process, but in the last year these have been reduced and a preliminary neutron lifetime measurement was acquired, yielding a value of 700±300 seconds, consistent with prior work. The substantial uncertainty is due largely to the remaining background events. During 2000, efforts will focus on background signal reduction. Plans include use of a larger confinement vessel, which would increase the primary signal but also improve light collection. Additionally, the UCN beam will be strongly filtered to further reduce off-energy neutrons and allow improved collimation to further decrease background events. These and other improvements may enable a hundredfold reduction in the uncertainty in the neutron lifetime measurement. Although this projection is optimistic, if achieved it would be a dramatic and outstanding accomplishment. This collaboration with Harvard University researchers should yield a number of significant fundamental papers beyond the initial results recently reported in Nature.

Another neutron lifetime experiment is the cold neutron beam lifetime experiment. In this case, β-decay protons are captured and their numbers measured. This is also a challenging process prone to experimental bias and vulnerable to detection inadequacies. Progress is being made by working closely with detector manufacturers and switching to passivated implanted detectors. Both neutron lifetime experiments have ambitious goals for 2000. This group of investigators is well skilled and well supported and is likely to achieve its goals.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

The group is pursuing new experiments exploring aspects of the weak interaction and concomitant parity violations. The goal is determination of the electron-neutrino asymmetry coefficient to a precision of ±0.5 percent. Extraordinarily careful measurement of the proton and electron decay products is proposed using a highly symmetric solenoid trap and coincidence detection. Initial modeling showed that an 18-day experiment would result in a precision of ±5 percent. Clearly, ±1 percent is possible, but ±0.5 percent may be especially difficult. No funds are yet available to pursue this effort.

NIST work in highly polarized 3He continues to reach new levels of achievement. The focus of this work is the development and application of neutron polarizers. In addition to their use in condensed matter and fundamental physics experiments, they are of interest to medical researchers pursuing polarized-gas magnetic resonance imaging. Larger cells with a greater percentage of polarized 3He have been developed. NIST is a national leader in this area, and NIST cells are now used routinely for neutron spin filters at major neutron sources nationally. New neutron source beam lines at NCNR will be designed to use polarized neutron beams. This work is a significant accomplishment that demonstrates the impact of NIST results on the greater scientific community.

The Neutron Dosimetry and Interactions Group maintains the databases for neutron cross sections and the international Evaluated Nuclear Data File (ENDF). Neutron fluence standard work continues at a steady pace. For the most part, developments are incremental and driven by user needs. Defense contractors and defense laboratories consider NIST fluence calibrations essential. The neutron manganese bath facility is employed for neutron source strength determination, comparing customer sources with the national standard. This facility was recently refurbished and modernized. NIST provides one of the few places internationally to accomplish such work. The modernization of these facilities is to be commended.

Work on the neutron cross section is now largely the effort of one individual; nonetheless, NIST maintains a viable and worthwhile presence in this area, with three projects under way. Measurement and analysis of the absolute H(n,p) scattering cross section, the angular distribution that is seminal to many fluence determinations, is a collaboration between NIST, Ohio State University, and Los Alamos National Laboratory. Preliminary work is already resolving some confusing data near 15 MeV. Related to this cross section and perhaps even more important at energies from 20 to 200 MeV is the 235U(n,f) cross section. NIST is deeply involved in this evaluation, which will be included in the ENDF. The 235U(n,f) and 238U(n,f) cross sections are rapidly becoming the “gold standard” of measurement capability. Continued NIST participation in international measurements of these properties, albeit at a modest level, is important. The ability to make these measurements reliably is fundamental to the nation's capacity to deploy a variety of high-energy neutron applications for many purposes, from deep-space probes to the management of nuclear power waste and to nuclear weapons stockpile stewardship. NIST is also participating in a cross-section test using the pulsed-beam iron sphere benchmark technique, which involves integral and differential measurements inside and outside an iron sphere. This program, which is DOE-funded, is relevant to particle transport and heating studies in iron, a common material in fission and fusion reactor design.

The recently completed Neutron Interferometry and Optics Facility is based on large new interferometer crystals of NIST design and can operate over a wavelength range of 0.2 to 0.45 nm with fringe visibility as high as 88 percent. The facility has been used to image the water distribution in fuel cell membranes and has most recently been applied to moving objects. A rotating computer drive has been imaged to indicate the presence of lubricants and functioning of gear mechanisms. Although fairly high resolution neutron tomography has been demonstrated, its applicability to larger structures and in biological areas has not yet been realized. This facility represents an excellent integration of unique capabilities with diverse application interests that could welcome a broader base of cooperative re

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

searchers and CRADA participants from industry. Completion of this facility is one of the Neutron Interaction and Dosimetry Group's most notable recent achievements.

The Radioactivity Group focuses on standards and methods, metrology for nuclear medicine, metrology and monitoring in the environment, and traceability. It is largely responsible for establishing and maintaining the primary standards for radioactive counting, which are provided by NIST as a service to the technical and scientific community. As a result, many of the Radioactivity Group's functions are related to the maintenance and development of SRMs. Another important aspect of the group's activities is participation in round-robin comparisons of proposed standards involving both national and international laboratories. The group also provides expert consultation to two international agencies in connection with such comparative measurements and is active in test rounds of standards with DOE reference laboratories.

Much of the Radioactivity Group's activities seek to enhance analytical methods. For example, an upgrade of the gamma-ray spectroscopy facilities is in progress, and improvements have been made in phosphor plate imaging techniques and in analyzing tritiated water. Work continues on the development of glow discharge resonance ionization mass spectrometry for radioactive materials. This system was successfully tested, and improvements are under way to increase the sensitivity of the instrument. This capability was obtained at considerable effort by modifying a thermal ionization mass spectrometer. The group's modest capital expenditures have all been related to such improvements in instrumentation.

Research on developing a new radiation imaging system based on a technique to store images in a thin coating of a photostimulable phosphor is intriguing; such a system could be used for radioactive measurements of large area sources. If developed successfully, this technique could be of major value to the DOE's decontamination studies of structures with low levels of radioactivity spread over wide areas.

In May 2000, members of the division participated in a workshop, “Micro-Radiation Level Measurements and Standards for Public and Environmental Radiation Protection,” sponsored by the Conference of Radiation Control Program Directors. Unfortunately, the Radioactivity Group does not have sufficient staff to follow up on the recommendation that came out of this well-attended workshop.

The group is also devising an imaging methodology involving gamma-ray scanning for the drums of radioactive materials sent to the recently opened DOE Waste Isolation Pilot Plant repository. Similarly, in basic calibrations and standards, further development of low-activity gamma-ray spectroscopy and microcalorimetry is progressing.

Another topic that could have significant value is the study of radionuclide speciation in soils and sediments. Leaching protocols are being developed for use. However, most leaching techniques suffer from incomplete separations, and the failure to identify the degree to which the separations are effective can lead to misinterpretations of the data. It is very important that the NIST study document the limitations as well as the advantages of these sequential separations. The degree of isolation and purification of different species should be reported with their uncertainties in each step of the techniques being studied.

The Radioactivity Group has provided an SRM for low-level radioactivity in ashed bone and is in the process of developing similar SRMs for a variety of soils, including one for the soil at the DOE's Rocky Flats Environmental Technology Site. However, the Rocky Flats cleanup is scheduled for completion by 2006; an SRM might not be developed in time to be of sufficient usefulness. It would seem more useful to develop SRMs for soils from the Hanford site (dry soil) and the Savannah River site (wet soil). Both of these areas will have continuing cleanup activities for more than 20 years. An SRM for either or both (preferably both) Hanford and Savannah River soil types should be of much value to the DOE decontamination effort.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

Concerning the analyses of radioactive components in soils and sediments, the Radioactivity Group would do well to establish key contacts with colleagues in DOE laboratories. Dialogue is needed to avoid both duplication of effort and work on problems in which the Radioactivity Group can have only minimal influence. Likewise, any involvement of the Radioactivity Group in issues involving nuclear waste and waste disposal related to weapons systems should be questioned. Ancillary issues of security and security clearances may preclude these from being viable areas of activity for this group. Cutbacks in staff would warrant a more judicious use of current personnel.

Impact of Programs

The Ionizing Radiation Division appears to evaluate the quality and impact of its work by several techniques. Among these are (1) the response of the customer to its efforts, (2) the interest and enthusiasm generated in the scientific community by its efforts, and (3) internal review of the publications and new science evolving from its programs. These somewhat general tools reflect the diverse nature of the division. For example, the calibration and standards work is very service driven, but the UCN neutron facility is a tool of exceptional strength for investigating fundamental aspects of particle interactions and materials research. As the panel has mentioned in prior reviews, a more strategic approach to research programs, facilities, and participation in standards organizations would be beneficial.

A strategic approach is especially needed for databases. To a large degree, NIST is, or could be, the source of several significant atomic and nuclear databases. A laboratory-wide evaluation of what databases are needed, how they should be maintained and improved, and how they should be promulgated is essential. This same point was made last year, and the panel notes that some progress has been made.

The division has been responsive to measurement programs and priorities as outlined by the Council on Ionizing Radiation Measurements and Standards and has been a strong participant in the CIRMS annual meetings and targeted workshops. The CIRMS Executive Committee has indicated that many of the measurement program descriptions have been completed or that significant progress has been made on most of the programs defined in the 1998 issuance of the second CIRMS National Needs Report. 2 However, there is some concern about whether the division is adequately staffed to carry out the opportunities as outlined by CIRMS. CIRMS looks forward to the division's participation in the development of the third National Needs Report, to be published in 2001.

Other measures of dissemination and impact, such as publications in leading scientific journals, are excellent. The ever-increasing group of users and industrial partners is very encouraging and is indicative of the high regard for NIST research and capabilities. The panel is also pleased with the strong participation of NIST scientists in activities sponsored by the American Association of Physicists in Medicine and the International Commission of Radiation Units and Measurements. These are significant markers of recognition of the excellence of the NIST effort.

External industrial and scientific interaction with the division is most enhanced when the division demonstrates that it has unique, state-of-the-art equipment and facilities. The talent base within the division is quite strong, but this in itself may be insufficient to foster the development of more industrial interactions. Noteworthy is the exceptional level of major corporate cooperation and joint program efforts with the Neutron Interactions and Dosimetry Group, which has unique, state-of-the-art facilities.

2  

Council on Ionizing Radiation Measurements and Standards, Second Report on National Needs in Ionizing Radiation Measurements and Standards, October 1998. See <http://www.cirms.org/CNNRcover.pdf>.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×
Division Resources

Funding sources for the Ionizing Radiation Division are shown in Table 5.5. As of January 2000, staffing for the Ionizing Radiation Division included 33 full-time permanent positions, of which 29 were for technical professionals. There were also six nonpermanent and supplemental personnel, such as postdoctoral research associates and part-time workers.

Since the previous assessment, a significant upgrade was made in calibration facilities. These included modernizing photon-range apparatus, some radiation sources, data acquisition tools, electronics, benches, general painting and refurbishing, and so forth. The effect is dramatic and moves NIST toward a physical and technological infrastructure consistent with the mission and the national and international prominence of NIST. These changes were long overdue and must not stop. Much remains to be done in the calibration facilities before NIST can claim an international leadership position. The division would benefit from a complete review of existing facilities and the development of a full modernization program consistent with its mission. The Radioactivity Group is also renovating a high-level radiochemistry laboratory to address logistical and safety concerns. This laboratory should provide a major and valuable resource to the group. It seems to be designed to provide good access with reduced exposure of workers to radiation and will be of considerable value, particularly in studies related to the use of radionuclides in nuclear medicine, which frequently require higher levels of activity.

High-quality calibrations and standards demand similar quality in people and facilities. Young, qualified scientists are in short supply and will only join organizations committed to excellence. This is readily apparent when considering the UCN facility and the high quality of its staff and results. The age profile of the division continues to broaden as younger, very qualified talent is brought in to replace retirees. These developments are laudable and augur well for continuing notable accomplishments.

A good portion of the division's capital expenditures and planned capital expenditures relates to replenishment of radioactive cobalt-60 (60Co) sources. Although the national reference source used for dosimetry was replenished, its housing and related methods of exposure are no longer on a par with state-of-the-art facilities found in industry and other institutions. It is encouraging to note that one of the

TABLE 5.5 Sources of Funding for the Ionizing Radiation Division (in millions of dollars), FY 1997 to FY 2000

Source of Funding

Fiscal Year

1997 (actual)

Fiscal Year

1998 (actual)

Fiscal Year

1999 (actual)

Fiscal Year

2000 (estimated)

NIST-STRS, excluding Competence

4.1

4.3

4.5

4.3

Competence

0.3

0.0

0.0

0.0

ATP

0.1

0.2

0.2

0.2

Measurement Services (SRM production)

0.2

0.1

0.1

0.1

OA/NFG/CRADA

1.1

1.5

1.6

1.9

Other Reimbursable

0.8

0.8

0.9

0.9

Total

6.6

6.9

7.3

7.4

Full-time permanent staff (total)a

37

35

36

33

NOTE: Sources of funding are as described in the note accompanying Table 5.1.

a The number of full-time permanent staff is as of January of that fiscal year.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

smaller 60Co irradiators may be replaced with a contemporary unit. With the short half-life of 60Co, such source replenishment should be easy to incorporate into a much-needed, long-term capital plan. The manganese sulfate bath required in neutron dosimetry work was also refurbished. The capital for this and other significant items necessary for cold neutron experiments was obtained as an advance rather than as part of an overall divisional long-term capital plan.

The Radiation Interactions and Dosimetry Group's successes in establishing standardization procedures for mammography exposures, for calibrating brachytherapy seeds, and for reference calibrations of dosimeters have enhanced the division's national and international reputation. As demand for these core services increases, there must be a concurrent plan to provide sufficient staffing to maintain a high degree of responsiveness. NIST is also taking a more prominent role in water-based high-energy calibrations. This will require a fully functional water calorimeter and a high-energy bremsstrahlung beam. Given the rapid move to water-based high-energy dosimetry, NIST needs a comprehensive plan to ensure that the secondary accredited laboratories are able to deploy such calibrations in a cohesive manner.

During prior evaluations and in its present evaluation, the panel has routinely commented on how the aging and poorly maintained equipment in certain areas represents a serious and dangerous situation. In the present review, the panel notes with enthusiasm the improvements accomplished since its previous assessment. However, much remains to be done. For example, the revitalization of an antiquated 500-kV accelerator for use in alanine dosimetry work is laudable, but the division needs a capital plan to retire antiquated accelerators and replace them with state-of-the-art equipment. These NIST facilities compare poorly with those available at other national laboratories, such as the Japan Atomic Energy Research Institute in Takasaki. The ability to entertain greater industrial participation in NIST projects is severely hampered by this equipment. The Ionizing Radiation Division needs to clearly define what apparatus will be necessary to accomplish its mission and ensure that NIST maintains a world leadership position in support of the U.S. industrial base and research infrastructure. It may be that not all standards work can be maintained at the desired level and that some portions must be dropped to ensure that the most essential aspects of the program are in the optimal state. This requires a full planning process that provides precise near-term direction and places longer-time-line activities in a position aligned with the stated mission.

The division would greatly benefit from a 3-year plan for activities, improvements, and budget. Such a plan would also greatly improve the panel's review process.

The loss of key personnel to administrative functions is a concern. The Neutron Interactions and Dosimetry Group has had to scramble to cover its obligations under Nuclear Regulatory Commission contracts and to maintain its programs involving the long-term neutron effects on reactor pressure vessels. Improved human resources planning would enable the division to better adjust to such shifts in personnel assignments.

Although the division has been able to upgrade and increase the facilities available to determine radioactivity levels, there is not adequate staffing to support the growing demand in this area. The Radioactivity Group has most notably suffered from personnel cutbacks. The CIRMS has expressed concern about NIST's ability to pursue opportunities in the development of measurements and standards at the microradiation level.

To summarize, budgetary allocations within NIST have constrained the Ionizing Radiation Division such that its growth has not kept up with the demands of industry and the professional community. Greater opportunities for outside funding and collaborative projects could materialize if capital and personnel were allocated to this division commensurate with its potential. Unlike many other areas of technology being developed at NIST, ionizing radiation tends to be very capital intensive in its research

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

and in its industrial use. A long-term (3- to 10-year) capital and personnel plan would benefit both the division and NIST.

Time and Frequency Division
Division Mission

According to division documentation, the mission of the Time and Frequency Division is to support U.S. industry and science through provision of measurement services and research in time and frequency and related technology. To fulfill this mission, the division engages in the development and operation of standards of time and frequency and coordination of them with other world standards; the development of optical frequency standards supporting wavelength and length metrology; the provision of time and frequency services to the United States; and basic and applied research in support of future standards, dissemination services, and measurement methods.

The programs of the division at this time are well aligned with and strongly support its stated mission and the missions of the Physics Laboratory and NIST.

Technical Merit and Appropriateness of Work

The frequency and time program continues to rank overall as probably the best in the world. It has a very effective mix of basic science, frequency standard and time transfer technique development, and time and frequency services. The past year has seen significant advances in all areas, including advances in optical frequency standards that seem to point the way toward an entirely new generation of time and frequency standards. The division's future should continue to be bright provided it remains aware of the need to maintain its technical expertise in important areas.

For several years, the U.S. primary standard has been a state-of-the-art optically pumped cesium beam, NIST-7. Over the last year, the cesium atomic fountain, NIST-F1, has undergone a thorough evaluation. The fountain represents an improvement over the beam in a number of ways, including its linewidth (1 Hz), which is a factor of 60 less than NIST-7. The division's plan to have NIST-F1 take over as the primary standard sometime in the next year appears sound. Even in its present form, the fountain's performance exceeds that of the beam, and improvements are undoubtedly possible. For example, transverse cooling of the fountain's beam would improve its performance in terms of both accuracy and stability, and this is under consideration, perhaps in a second-generation device. Ultimately the cesium fountain seems to be limited to an accuracy of about 0.5 × 10−15 by the collisional spin exchange frequency shift. Rubidium has a much smaller spin exchange shift and is under consideration as a highly stable working device for the realization of the second. The accuracy of NIST-F1 was previously limited by the precision with which the gravitational potential at the Boulder site was known. Recent work on this in conjunction with the University of Colorado has reduced the uncertainty surrounding the gravitational potential frequency shift to about 1 × 10−16.

The evaluation of NIST-F1 reported to the BIPM shows it to be the best in the world. However, the BIPM will not use its timescale measurements for helping steer the International Atomic Time (TAI) international timescale until that evaluation has been published. A copy of the manuscript submitted to Metrologia for publication was also given to BIPM so that NIST-F1 may soon contribute to the steering. Recent results from NIST-7 should be published soon.

The division continues its work on an advanced, laser-cooled cesium clock for space. The project is aimed at an improved realization of the definition of the second, improved coordination of time and

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

frequency standards on Earth, and tests of several aspects of special and general relativity. The NIST effort is somewhat behind a similar European project but is advancing rapidly. The actual clock will ultimately be built by the Jet Propulsion Laboratory, but the NIST Time and Frequency Division chief is the principal investigator.

There has been remarkable progress in the last year toward the realization of optical trapped-ion frequency standards with potential stability and accuracy well beyond those envisioned for cesium fountains. This progress included major advances with the 199Hg+ optical frequency standard, a demonstration that optical fibers can be used to do precise frequency comparisons between laboratories separated by distances of at least 100 m, and promising advances using mode-locked femtosecond lasers for optical frequency measurements. Taken together, these advances strongly suggest that there may be a rather clear path toward a completely new generation of frequency standards and a major technological return on more than two decades of investment in research with trapped ions, in addition to the substantial scientific return already realized.

A year ago, substantial progress had been made on the 199Hg+ microwave frequency standard at 40.5 GHz. The standard had demonstrated a stability of about 1 × 10−14 for interrogation times of 100 s. That work has been put on hold indefinitely because of recent very impressive advances with the 199Hg+ optical frequency standard. The advances have resulted from changes in the ion trap, putting the trap in a cryogenic environment, and eliminating sources driving excess ion motion. There have also been improvements to the local oscillator. The laser local oscillator for the S-D resonance at 282 nm has been improved to the point at which the beat frequency between two oscillators (at 563 nm) has a linewidth of 220 mHz. Using tight confinement in a small radio-frequency (RF) quadrupole trap has reduced the size of the ion motion in the trap and has made it possible to reach the Lamb-Dicke regime, where the amplitude of the ion motion is less than the optical half-wavelength. The cryogenic environment for the trap has reduced background gas and allowed confinement times of at least many days. Reducing the sources driving excess ion motion has now made possible observation of the optical transition at 282 nm with linewidths of about 3 Hz. This corresponds to a Q (ratio of the transition frequency to the linewidth) on the order of 4 × 1014, a truly remarkable achievement. The 199Hg+ standard has the potential to reach an accuracy of perhaps 1 × 10−16, but for the final standard, another ion will likely be chosen that does not have such a relatively large electric quadrupole shift in the line frequency.

The division is also working on an optical standard based on a narrow resonance in calcium atoms that are cooled and trapped in a magneto-optical trap. Cooling and detection are done with high-performance diode lasers, also developed by the group. The calcium frequency has very low sensitivity to electric and magnetic fields. The standard has demonstrated very good short-term stability. However, its linewidth, about 400 Hz, is much greater than that of the mercury ion and thus its potential for accuracy is not as good.

First demonstrated in Germany, frequency comb generation through locking of the repetition rate in a mode-locked femtosecond laser is being developed in the division to allow comparisons of optical frequencies such as the 282-nm line in 199Hg+ and the 657-nm line in neutral calcium. It appears possible that in the near future, this technique, which is much simpler than previous frequency multiplication and comparison schemes, could be used to connect the microwave and optical regions, opening the way for practical optical frequency standards. Recently, a spectral comb covering a range of 100 THz in the appropriate optical region has been demonstrated by the division.

Work on correlated states in ion strings continues. Four beryllium ions have now been trapped efficiently with their motional and internal quantum states entangled. This work has application not only to quantum computation but also to improving frequency stability in trapped-ion standards. This technique of producing correlated states appears to be more scalable than other techniques in use so far.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

Noise in the center-of-mass motion of the ion string has been detected and is thought to be due to fluctuating patch potentials on the quadrupole electrodes.

Work continues on the small gas-cell frequency standard. As well as working on the Raman transition, the group has demonstrated a standard based on coherent population trapping, which shows great promise for achieving a very compact, low-power device that fills a niche between high-performance quartz oscillators and atomic beam devices. This work has considerable potential for commercial and military use.

Phase and amplitude noise measurements and standards produced by NIST continue to lead the world, as does electronics for the primary frequency standards. The latest microwave synthesizer developed by the division has outstanding performance with regard to ambient effects and added phase noise. The performance is due in large part to the use of carefully designed regenerative dividers at the highest frequencies and digital dividers at lower frequencies. A phase noise measurement technique for microwave pulse amplifiers has been developed. It provides improvement of tens of decibels over previously available instruments. Many of the results from this electronics program have direct and important applications in industry. The division also performs many calibrations for industry in this area.

The stability of the NIST coordinated universal time (UTC) timescale with respect to the UTC disseminated by BIPM has improved greatly over the past several years. The use of five commercial hydrogen masers with cavity autotuning has contributed greatly to this. In the past year, the division also added new measuring equipment to replace 20-year-old equipment. The NIST timescale is now one of the two best in the world.

In addition to the important agreement signed last year on the equivalence of time and frequency between the U.S. Naval Observatory and NIST, the division has signed a declaration of measurement recognition with the National Research Council of Canada and the time and frequency division of Mexico's Centro Nacional de Metrología. This declaration states that the times and frequencies of the timescales from the three institutions are equivalent within certain limits.

The division's Internet time service is now receiving about 25 million hits per day, compared with 6 million a year ago. This is evidence of the continued, rapidly increasing importance of time synchronization. The division intends to transfer this Internet service to the private sector.

Time transfer via Global Positioning System (GPS) common view techniques, including carrier phase and two-way satellite transmission, is at the state of the art. The rapid advance of frequency standard accuracy and stability is already stressing the capability for frequency comparisons at separated locations via these techniques. This is clearly an important area for continued work and innovation, and such work is in the division 's plans.

The upgrade of the NIST frequency broadcast station WWVB is essentially complete. The station now radiates 50 kW, which is very beneficial for the rapidly increasing number of clocks that are synchronized to it.

In general, the technical work of the division is at the state of the art. In several cases, NIST staff are actually taking the lead in redefining the state of the art. Even in the few areas in which the division's projects are not quite at the cutting edge, they are not far from it. Overall, the programs and program plans are very appropriate for carrying out the division's mission.

Impact of Programs

The division produced 58 technical publications in the past year. The quality of these appears quite high. The detailed evaluations of NIST-7 and NIST-F1 should be published in Metrología as planned. Participation in conferences and workshops is very good. Delivery of time and frequency signals is

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
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appropriate and in wide use. The division's Web site is comprehensive and widely used. Its scientific personnel are highly respected internationally, and their help is often sought by other laboratories.

Much of the work on frequency standards is important to the development of commercial frequency standards. The upgrade of WWVB is having a positive effect on new clock and watch products. The Internet timing service is now widely used, and the division is working with two companies to transfer this service to industry. The National Association of Securities Dealers now requires that time stamps of the member dealers be traceable to NIST. The equivalence agreements with Canada and Mexico support U.S. trade with these countries.

Division Resources

Funding sources for the Time and Frequency Division are shown in Table 5.6. As of January 2000, staffing for the Time and Frequency Division included 39 full-time permanent positions, of which 35 were for technical professionals. There were also 10 nonpermanent and supplemental personnel, such as postdoctoral research associates and part-time workers.

A major strength of the division is the high quality of its personnel. The division's practice of giving much freedom to its scientists clearly works to the benefit of the whole enterprise. The division staff display excitement and enthusiasm about their work, and many outstanding postdoctoral scientists and guest scientists are attracted to work there. Division scientists have demonstrated not only outstanding ability to create and develop new ideas and techniques but also are able to act on ideas from the outside and get up to speed and at the technical forefront quickly.

The Time and Frequency Division is reasonably well supported, and the resources appear adequate at present. The people and the programs that are proposed are of such high quality that good use could be made of additional resources, were they available. The planned move of the Ion Storage Group into better, contiguous space will be very beneficial. Further consolidation of the division's space would be worthwhile.

Outside funding is at the 40 percent level, somewhat higher than desirable for good control of the technical programs. New money is not coming in to support the services provided by the division, so

TABLE 5.6 Sources of Funding for the Time and Frequency Division (in millions of dollars), FY 1997 to FY 2000

Source of Funding

Fiscal Year

1997 (actual)

Fiscal Year

1998 (actual)

Fiscal Year

1999 (actual)

Fiscal Year

2000 (estimated)

NIST-STRS, excluding Competence

5.2

5.9

6.0

5.7

Competence

0.6

0.3

0.0

0.2

ATP

0.1

0.0

0.1

0.1

OA/NFG/CRADA

1.9

1.9

2.6

2.7

Other Reimbursable

0.7

0.7

0.6

0.8

Total

8.5

8.8

9.3

9.5

Full-time permanent staff (total)a

42

38

40

39

NOTE: Sources of funding are as described in the note accompanying Table 5.1.

a The number of full-time permanent staff is as of January of that fiscal year.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
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more automation and cost cutting must take place for NIST to be able to meet customer needs in this area.

MAJOR OBSERVATIONS

The panel presents the following major observations:

  • The technical merit of programs in the Physics Laboratory remains very high, with many projects at or defining the state of the art.

  • The four areas of opportunity presented to the panel—nanotechnology, biophysics, medical physics, and quantum information —have great potential for economic importance and build on existing strengths of the Physics Laboratory. Most are highly interdisciplinary in nature and would benefit from a coordinated approach across the relevant NIST laboratories to fully leverage resources. They represent appropriate avenues for the Physics Laboratory to pursue as it anticipates future measurement and standards needs in industry.

  • PL's industrial contacts must be chosen and pursued in such a way to ensure that the laboratory is anticipating future industrial needs rather than reacting to current needs.

  • Policy for protecting and disseminating NIST's intellectual property needs to be revisited. Several projects in the laboratory have considerable potential worth, and policy should provide incentives to both the laboratory and the individual investigator to pursue intellectual property protection appropriately.

  • Significant deficiencies in capital equipment and facilities continue to hamper PL's productivity. Such deficiencies can seriously compromise NIST's ability to hire and retain first-class scientists.

  • New funding would be required to mount serious new efforts in areas such as nanotechnology, biophysics, medical physics, or quantum information. More aggressive advocacy for funding for the laboratory programs seems necessary.

REVIEW OF JILA

This biennial assessment of the activities of JILA, an institute administered jointly by the National Institute of Standards and Technology and the University of Colorado (CU), is based on a meeting of the Subpanel for JILA in Boulder, Colorado, on February 8-9, 2000, and on documents provided by JILA. Note that NIST participation in JILA formally occurs through the Quantum Physics Division of the Physics Laboratory. One member of the Time and Frequency Division is also a JILA Fellow.

Members of the subpanel included Frances A. Houle, IBM Almaden Research Center, Chair; A. Paul Alivisatos, University of California at Berkeley; Robert W. Field, Massachusetts Institute of Technology; George W. Flynn, Columbia University; E. Norval Fortson, University of Washington; Mark Kasevich, Yale University; Steven S. Vogt, University of California Observatories/Lick Observatory; Ian A. Walmsley, University of Rochester; and Carl A. Zanoni, Zygo Corporation.

Mission

According to personnel at JILA, the mission of the NIST Quantum Physics Division (QPD) is to support the U.S. economy by working with industry and academe to advance the frontiers of measurement science and commercialize the results of its endeavors. In pursuit of this mission, the division

  • Develops the laser as a precision measurement tool;

  • Determines fundamental constants and tests the fundamental postulates of physics;

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
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  • Exploits Bose-Einstein condensation as well as quantum degenerate Fermi gases for metrology and low-temperature physics;

  • Devises new ways to direct and control atoms and molecules;

  • Characterizes chemical processes and their interactions with nanostructures; and

  • Studies the interaction of ultrashort light pulses with matter.

The subpanel believes that QPD's work in the areas of precision measurement; low-temperature states of matter; development of ultrahigh-sensitivity, ultrahigh-resolution, and ultrashort timescale laser-based metrologies; determination of fundamental constants; and characterization of chemical processes is closely aligned with the needs of NIST and the execution of the division's mission. These measurement and standards activities promote the U.S. economy and public welfare by providing world-class technical leadership and ensuring the availability of essential measurement capabilities and reference data. Through its participation in JILA, QPD's contributions are long term in nature, providing a strong foundation for future optically based technologies. Commercialization of its endeavors takes place through transfer of basic technologies by publications, lectures at conferences and research institutions, patents, interactions with industrial scientists and engineers, and training of students who go on to industrial careers. Because NIST no longer supports astrophysics research at JILA, these activities are not included in the QPD mission statement. The research carried out by CU and the NIST Fellows contains so many interconnections, however, that it is not possible to cleanly separate out NIST work for the purposes of this review. Accordingly, this report presents current activities and accomplishments from all of JILA, including contributions of the astrophysics Fellows.

NIST gains enormous leverage from its partnership with CU at JILA, as evidenced from the excellence of the work presented to the subpanel. Continued nurturance of this partnership by NIST and CU will ensure that this premier research institute retains its world-class status and continues to provide a critical foundation for future U.S. technology development.

Technical Merit and Appropriateness of Work

The science and technologies produced by JILA are truly superb, placing this laboratory at the forefront worldwide. JILA Fellows have recently received a number of prestigious awards for their research, including the R.W. Wood Prize, the Schawlow Prize for Laser Science, the Benjamin Franklin Medal in Physics, the Lorentz Medal, the William F. Meggers Award, and the Alexander von Humboldt Research Award, as well as a number of fellowships and honorary lectureships. JILA's excellence does not happen accidentally: it is the result of the partnership between the two sponsoring institutions, CU and NIST, and dynamic, ongoing collaborations among the Fellows and with external institutions. These strong and successful connections, together with inspired management, stable and flexible funding, and outstanding technical support, set JILA apart from most institutes. It is a preeminent model for how partnerships can foster a great national resource. Research at JILA falls into five technical areas: (1) fundamental and precision measurements, (2) optical and nonlinear optical physics, (3) materials interactions and characterization, (4) atomic and molecular interactions and chemical physics, and (5) astrophysics. JILA also maintains an important program in time distribution. Active work in these areas is described in this section, after a brief section of technical highlights.

Highlights

Over the past 3 years, JILA has focused on the future directions of its technical program through recruitment of excellent new Fellows and Fellow-track scientists primarily in the areas of optical,

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
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atomic, and molecular physics. Four of these new hires presented summaries of their research programs and recent accomplishments to the subpanel during its visit. It is an understatement to say that the subpanel was extremely impressed by the originality, elegance, and vitality of the work of these Fellows and their collaborators. The speed with which the new Fellows have integrated themselves into JILA through the establishment of numerous important collaborations with the senior Fellows is astounding and a testament to the success of JILA's recruitment process and to its tradition of collaboration. Two of the projects presented are highlighted here. Any institution the size of JILA would be pleased to have just one achievement of this caliber every few years. As noted above and described in the highlights and the rest of the “Technical Merit” section, however, numerous excellent projects are under way at JILA that open new fields, build new synergies between areas of research, and develop recent discoveries.

A New Marriage Between Precision Measurements and Nonlinear Optics. JILA's collaborative culture and environment have once again led to a striking success, this time through a synthesis of traditional JILA expertise in laser stabilization with its newly developed strength in the field of short-pulse nonlinear optics. Until now, progress on optical frequency standards was limited by the difficulty of multiplying the radio-frequency primary standard up to optical frequencies and the very sparse coverage of known optical standards. Using a train of laser pulses to link the optical frequency directly to an RF time standard, the JILA group has taken a revolutionary step toward a calibrated optical frequency standard and a general-purpose optical spectrometer of unprecedented accuracy. The laser is mode-locked at an RF repetition rate set by an atomic clock, sending out an accurately timed train of short pulses of about 100-nm optical bandwidth. The bandwidth is then broadened much further by four-wave mixing in an optical fiber, to the extent that the fundamental optical frequency band overlaps its second-harmonic band. Comparing these two harmonics permits the optical frequency, which has been stabilized against an atomic or molecular absorption line, to be measured in terms of the RF mode spacing. Eventually it should be possible simply to dial to any desired laser frequency and have it automatically calibrated by the best available time standard.

Fermi Degenerate Gas. Pioneering work at JILA has once again opened a new field, degenerate Fermi atomic sources, with JILA investigators at its forefront. Degenerate Fermi atomic sources have potentially important applications for precision measurement (time standards, etc.) since, unlike Bose systems, they do not suffer from density-dependent perturbations. After the 1995 demonstration of Bose-Einstein condensation at JILA, many groups recognized that similar experimental techniques might be used to produce degenerate Fermi systems comprised of ultracold fermionic atoms. Unlike bosons, no two fermions can occupy the same quantum state; thus, the behavior of ultracold Fermi systems differs in fundamental and universal ways from that of their bosonic counterparts. In a remarkable achievement, JILA researchers were the first in the world to observe the onset of degeneracy in an ultracold, atomic Fermi system. Evaporative cooling and laser cooling techniques similar to those used at JILA to create high phase space densities for bosonic systems were used to cool atoms of potassium-40 (a composite fermion) to temperatures of about 100 nK, where the onset of degeneracy was observed through modifications of atomic momentum distributions.

Fundamental and Precision Measurements

In its fiscal year 1998 report, the subpanel saw “the long-standing programs in precision measurement and metrology ” as “essential forces in creating the high standing and impact of JILA. ” In this report, the subpanel finds that the quality of these programs remains extraordinarily high. Work on

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
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fundamental measurement techniques continues to produce new results of importance both to fundamental science research and to evolving industries.

As highlighted above, a recent breakthrough at JILA enables stabilized optical frequencies to be linked with radio-frequency time standards in a single step, a development that should revolutionize precision optical standards and measurements that are of importance for emerging telecommunications industries. JILA, long a world leader in the stabilization of lasers, recently locked a Nd:YAG (neo-dynium:yttrium-aluminum-garnet) laser to a narrow molecular line of iodine with world-record stability. The breakthrough came by combining this technology with new JILA expertise in nonlinear optical physics, discussed in the next section. This work was supported by NIST Competence funding.

JILA made news 2 years ago with its precise measurement of atomic cesium parity violation, which probes for new physics beyond the electroweak standard model. Since that time, JILA measurements of Stark shifts in cesium have helped to show that the atomic theory of cesium may be more accurate than previously thought, with a smaller error in the calculation of parity violation. Using the smaller uncertainty, there appears to be a significant deviation between atomic parity violation and the electro-weak standard model. This has important implications for elementary particle physics.

Other admirable advances in fundamental measurement techniques have been made since the last assessment. For example, a new type of far-off-resonance dipole trap for cold atoms that uses circularly polarized light has been successfully demonstrated, with possible applications to new measurements of parity violation. Cavity-enhanced optical absorption methods have been improved as a way to detect tiny absorption by molecular overtone lines or trace quantities of atoms and molecules. Two gravity projects have recently produced results, one yielding a compact instrument for field-portable absolute-g measurements, the other producing a dedicated apparatus to measure the Newtonian gravitational constant (G) and help resolve large discrepancies between published determinations of this fundamental quantity.

Optical and Nonlinear Optical Physics

The success of several recent experiments in the ultrafast regime has placed JILA at the forefront of optical physics and nonlinear optics. Significant contributions have been made to advancing spatiotemporal coupling in nonlinear pulse propagation, with connections to continuum generation and telecommunications; phase stabilization of mode-locked lasers, with applications to precision measurement; and generation of high-harmonic radiation, with applications to materials science and biophysics. Recent hires in this area greatly enhance the nonlinear optics effort at JILA and promise to sustain the visibility of the research and educational programs. Two examples of outstanding work in optical and nonlinear optical physics are given below.

The development of the first stabilized multiterahertz frequency comb by a collaboration of JILA expertise in laser stabilization methods and precision time measurement, as described in the highlights above, promises a new era in precision measurement and immediate applications to frequency standards and to atomic spectroscopy across a broad range of wavelengths. An integral part of this success was a specific application of nonlinear optics. The standard method of frequency calibration relies on a comparison of the spectrum of second-harmonic radiation with the fundamental from which it is generated. The team used a novel photonic crystal fiber from Lucent Technologies to generate a broad continuum of radiation from a relatively narrowband input (at least by ultrafast laser standards). The continuum is generated by four-wave mixing in the fiber, which is properly phase matched at a nominal wavelength of 800 nm by virtue of the anomalous dispersive properties of the fiber. This continuum extends as far as the second-harmonic spectrum of the input, allowing a direct comparison of the extended frequency comb of the continuum-enhanced fundamental with its second harmonic. By

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

nulling the beat note between neighboring modes in the two spectra, the frequency offset of the fundamental can be set to zero, meaning that the absolute phase of the pulses in the train output of the mode-locked oscillator is automatically zero. Stabilization of the cavity period to a timing signal derived from an atomic clock guarantees that the beat note fluctuations do not arise from drifts in the cavity length, so that a separate feedback loop adding a frequency-dependent length to the cavity can be used to control the absolute phase. This makes the entire system quite simple and robust and provides a broadband source referenced to a clock standard.

This feat could not have been accomplished without the colocation of experts in ultrafast lasers, nonlinear optics, laser stabilization, and precision timing. JILA is virtually the only place in the United States, and one of only a handful of places in the world, where such groundbreaking work could happen. Such synergy is a hallmark of JILA science, and the subpanel is heartened to see it strong and vital. This accomplishment will also impact other nonlinear optics research within JILA. For instance, several recent calculations indicate that the absolute phase of an ultrashort optical pulse (the relative time at which the peak of the envelope and the nearest peak of the carrier pattern are maximum) will play a central role in determining the ionization dynamics of atoms and molecules and therefore possibly in determining the efficiency of x-ray generation. This is something ideally suited for exploration at JILA, because two of the world 's experts in x-ray generation are located in laboratories adjacent to the stabilized optical frequency standard experiment.

JILA's two recent hires in x-ray generation have quickly moved to set up new facilities and are already making significant progress in the generation of vacuum ultraviolet and extreme ultraviolet (EUV) radiation. Of particular note is their demonstration of a novel coherent control method for engineering the spectrum of x-ray wavelengths generated by the photoionization of noble gases in capillaries. This method, in which details of the temporal shape (and phase) of very short pulses may be manipulated in order to optimize as few as three peaks in the x-ray spectrum, suggests that control circuitry will soon be an integral part of all ultrafast laser systems. There is no better place than JILA to undertake such studies. For example, design and fabrication of a new low-pressure, hollow-core fiber gas cell were significantly advanced by the expertise of the glass and machine shops. The simplicity of the design that resulted will make it a technological standard for this work and will enable the proliferation of tabletop, laser-based x-ray sources and the myriad applications likely to result.

Materials Interactions and Characterization

Over the past few years, JILA has capitalized on its tremendous knowledge and experience in optics to provide new tools and methods for characterization of electronic materials. JILA brings its strength and experience in instrumentation development, photonics, and optics to bear on an important class of problems, developing a capability with a tremendous opportunity for future growth.

Several investigators are participating in a very successful program using NSOM, an initiative supported by NIST Competence funds. Two experimental scientists have taken advantage of the intense, localized electric field enhancements that occur near the tip of an atomic force microscope probe to sample nanostructures in an evanescent laser field with 2- to 10-nm-scale resolution. A theoretician has joined this collaboration, looking at the theory of nanoscale field effects. The newest thrust has been toward single-molecule confocal microscopy, which now allows the spectroscopic isolation and study of single molecules, fluorescent proteins, and nanostructures in the condensed phase. These methods were most recently used to probe slow recombination dynamics of electron hole pairs in single CdSe semiconductor quantum dots, which are responsible for “blinking” (i.e., abrupt transformation back and forth between optically “bright” and “dark” states). JILA researchers have been able to

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
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observe these recombination dynamics over an unprecedented dynamic range (nine orders of magnitude), which has revealed intrinsically nonexponential kinetics that result from and provide a measure of the dense, inhomogeneous distribution of electron-hole trap states in 3-nm nanostructures.

Another JILA scientist has developed several new scanning near-field probes, most notably a scanning IR near-field microscope. Using tapered, infrared, transparent fiber-optic tips and a 3-µm tunable color center laser, a spatial resolution of 300 nm (one-tenth the wavelength of the IR probe light) has been obtained, as well as an impressive absorption sensitivity of 0.01 percent transmittance. This was accomplished by probing OH absorption band modifications in patterned poly(t-butylmethacrylate) polymer containing 5 percent by weight of the photoacid generator triphenylsulfonium hexafluoroantimonate deposited on sapphire substrates, a collaboration with IBM. The IR microscope transmission at two different wavelengths shows a remarkable change in contrast with infrared wavelength. The results of these studies offer the possibility to probe acid diffusion lengths for ever-decreasing size line features in semiconductor lithography.

Three recently hired Fellows extend the materials program to include nonlinear time-dependent techniques. One of these Fellows has established an experimental program in studies of photon echoes, dephasing, and wave-mixing experiments in quantum well and quantum dot samples and is using second-harmonic generation techniques to characterize the Si-SiO2 interface. The two others have joined with an established Fellow to pursue the use of ultrafast x rays to measure photoelectron spectra during reactions and dissociation of species in the gas phase and adsorbed on surfaces. The core-level shifts thus obtained provide direct information about the chemical environment and bonding of atoms and allow the reactivity and chemistry of these species to be followed. These x-ray sources based on ultrafast lasers promise to complement synchrotron radiation as a convenient and transportable means of chemical analysis.

The biggest issue faced by the JILA materials program is the development of closer ties to nearby research groups that produce and study advanced electronic materials, since more rapid development of new, advanced materials occurs when the growth, characterization, and study occur in continuous feedback. JILA has a genuine opportunity to influence nearby institutions and to enhance its program through additional coupling with programs going on at the University of Colorado campus and at NIST Boulder. There appears to be opportunity for more fruitful collaboration with materials researchers in the CU chemistry, physics, and materials science departments and in the NIST Boulder laboratories. Some collaborations are already occurring, but more seem possible.

Atomic and Molecular Interactions and Chemical Physics

JILA investigators continue to lead the world in experimental and theoretical investigations of ultracold quantum degenerate gases. Recent breakthroughs include the first realizations of a quantum degenerate Fermi gas of atoms, observation of vortices in Bose-Einstein condensates, and dynamic manipulation of the interaction strength in a rubidium-85 (85Rb) condensate. The realization of a quantum degenerate Fermi gas (described above) opens a new field of research. The vortex creation work evolved from a series of beautiful and important experiments aimed at clarifying the nonlinear dynamics of a system of two coupled Bose condensates. The 85Rb work enters exciting new experimental and theoretical territory in which existing paradigms might fail. The experimental program is tightly integrated with theory, an essential feature of the best-in-the-world status of this research.

Many of the new techniques being developed at JILA, such as femtosecond EUV, ultrasensitive and ultrahigh-resolution laser techniques, and phase-controlled 10-fs pulses, can be used to interrogate single molecules and create and probe localized excitations of large molecules and complex bulk

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

materials. Both approaches are valuable because they distinguish a simple system within a complex one and permit monitoring of the evolution of the simplest possible subunits of a larger system. This unites the interests of physical chemistry, which is increasingly concerned with complex systems, and of atomic, molecular, and optical (AMO) physics, which is probing new limits of simple systems.

Interest in coherent control and quantum computing is stimulating new research into phase control in atoms and molecules. Phase and amplitude control is investigated in the preparation and probing of vibrational and rotational wave packets. In new work at JILA, an eight-state phase control process has been demonstrated in a lithium dimer, in which eight states are simultaneously created in a superposition state with precise phase control of each state to about one degree of phase. The decoherence rates of these phase-controlled superposition states are being explored to determine their suitability for quantum computing.

New directions in ultrafast photophysics and the spectroscopy of complex systems and short-lived species are bearing fruit. One group is using the method of extended spectral cross-correlation to unravel the complex dynamics of the photodissociation of ammonia and all of its deuterated analogues via a graphical representation. The separation of fragment distributions by pattern recognition not only yields spectral patterns that are less complicated to assign but also reveals physical insights into the chemical process without even assigning the product spectra. The powerful combination of slit jet expansions and confined, pulsed discharges developed by another group now provides unprecedented capabilities for generating intense concentrations of highly reactive species such as hydrocarbon radicals and molecular ions, but under the greatly simplifying conditions of a supersonic cooled jet in which temperatures near 10 K can be achieved. This has permitted the first detailed spectroscopic investigation of many hydrocarbon radical species important in combustion processes. The assignment of these spectra via conventional room-temperature or elevated-temperature spectroscopy would have been experimentally intractable. These intense radical sources have also proven invaluable in crossed molecular beam studies, where they were used in conjunction with sensitive, direct IR laser absorption methods to facilitate the study of simple bimolecular reaction events at the single-collision, quantum state-to-state level of detail. A third group's investigations of ultrafast photodynamics in negatively charged gas-phase ionic clusters provide new insights in two important areas. Investigations of femtosecond-scale photoexcitation processes in solvated negative ions generate insights into the role of the solvent in mediating open dissociation channels (the “cage” effect). When the formation of an unstable neutral species, initiated by photodetachment of an electron from a stable polyatomic anion to form an unstable neutral species, is coupled with an ultrafast laser probe, the entire bond rearrangement reaction coordinate is revealed. Researchers at JILA and other institutions are working to connect phenomena found in gas-phase cluster work to similar condensed-phase behaviors, with notable initial success.

Astrophysics

At present, JILA employs seven astrophysics Fellows from the CU Astrophysical and Planetary Sciences (APS) Department and several adjoint Fellows who remain active in astrophysics-related research. The overlap in research interests between JILA's APS and physics and chemistry Fellows is not large, although in some areas such as gravity wave detection, there is a very productive interaction. APS Fellows are doing world-class research in many different areas and are at or near the cutting edge in most of these endeavors. They accounted for about 29 percent of the 1998-1999 publications by JILA scientists, essentially the same as their proportion of APS Fellows at JILA. Most of their publications were in highly respected peer-reviewed journals. A few highlights illustrate this.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
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Six JILA Fellows are involved in mission definition studies of the Laser Interferometer Space Antenna (LISA), a spaceborne laser interferometer mission for the detection of gravity waves. This is potentially a wonderful marriage of the unique prowess and experience of the QPD in laser-based metrology with cutting-edge astrophysics research. LISA will be capable of detecting gravity waves from the formation of massive black holes in galaxy mergers, from stellar collapse events and from compact star binaries in our own galaxy, thus opening a dramatic new window onto our universe. This relates to theoretical work at JILA on numerical simulation studies of the behavior of matter falling into and around black holes and compact stars. JILA efforts on LISA were recently rewarded when LISA became part of the NASA Office of Space Science's strategic plan. LISA is now being considered for a joint mission with the European Space Agency for flight in 2010.

Another JILA research group continues to be very active in designing and using spaceborne experiments (largely with the HST) to study many aspects of astrophysics, from detailed studies of the atmospheres and coronas of stars to detailed mapping of the structure of the local interstellar cloud. This group is also determining the relative abundance of deuterium, work that has enormous cosmological implications regarding the present baryonic density and ultimate fate of the expanding universe.

Theoretical astrophysics continues to thrive at JILA. One group has been working on computer models of the explosion from supernova SN1987A. It has developed detailed predictions of what to expect as the blast wave from the supernova slams into surrounding interstellar matter over the next few years. These predictions are now being tested with observations from the HST Imaging Spectrometer and the Advanced X-ray Astrophysics Facility and Roentgen Satellite. Another Fellow has been carrying out theoretical studies of astrophysical fluid dynamics with particular reference to the structure and dynamics of the Sun. He has been heavily involved in inverting helioseismology data to derive the interior rotation and dynamics of flow patterns in the Sun. This type of work is right at the cutting edge of both solar and stellar structure research. A third Fellow's group has also been carrying out theoretical studies in solar physics, involving three-dimensional simulations of the interplay of magnetic fields and convection in the Sun and the effects of this interplay on p-mode global acoustic oscillations. Again, this type of research is right at the forefront of work aimed at understanding the processes that drive the Sun.

The decision was made 2 years ago to transfer astrophysics from JILA to CU. The astrophysicists plan to move out of the JILA building and be cohoused with their CU colleagues; however the date for this move is uncertain because of lack of available space in other university buildings and lack of funds to construct new space. The present arrangement whereby a dwindling number of APS Fellows are housed at JILA is satisfactory for the near term, but JILA Fellows will have to think carefully about new hires when replacing retiring APS Fellows. A committee has already been established to work on this challenging issue. If suitable candidates can be found, it may be possible to replace retiring APS Fellows with scientists more closely involved with the laser-based metrology interests of the QPD. The LISA project—cutting-edge, space-based laser metrology applied to the detection of gravity waves—is one area in which such an appointment might make good sense. Other possible areas might be the development of superconducting tunnel diode detectors, far-IR or submillimeter detector development, or active and adaptive optics techniques.

Time Standard Distribution

The JILA Fellow from the NIST Time and Frequency Division maintains an important program in time standard distribution: NIST-authenticated time certification is becoming increasingly important in commerce, especially financial trading. This researcher has created an online time transfer service that

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
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is receiving 20 million hits per day and growing at a rate of 7 percent per month. In another project, he has addressed the problem of communicating extremely accurate time measurements to a distant user. Novel methods exploiting the high-frequency carrier rather than the lower-frequency signal of the GPS have been developed that are capable of transferring time measurements at 1 part in 1014 absolute accuracy.

Impact of Programs

The JILA programs are actively and effectively disseminated through technical publications, invited talks, and the guest researcher program. During 1998 and 1999, 218 technical papers were published, permanent and visiting JILA staff members gave 183 invited talks, and 50 guest researchers worked at JILA. An especially noteworthy example of the impact of the scientific work at JILA has been the creation of approximately 20 BEC laboratories around the world subsequent to the pioneering, successful BEC work done at JILA.

There is a plethora of technology at JILA of potential interest and value to industry, and it is part of NIST's mission to foster connections with, and support technology transfer to, industry. However, during the past 2 years, JILA efforts to foster industry connections and technology transfer to industry have been substantially less than during the previous 2-year review period. At the time of the previous review, one member of the JILA staff was spending 50 percent of his time coordinating industry activities. He is now spending 20 percent of his time on these activities. Furthermore, the number of distinguished visitors from industry has declined (one in 1996, one in 1997, two in 1998, and none in 1999), as have invited talks by industrial researchers (six in 1996, four in 1997, three in 1998, and one in 1999). Since the previous review, a National Science Foundation-funded Integrated Graduate Education, Research, and Training Award was provided to CU for its Optical Science and Engineering Program (OSEP). The staff member responsible for JILA's industrial outreach was named as assistant director, with the intention that JILA's industry activity would be driven through OSEP. This change may be related to the decline in JILA industry activity. Industry connections and technology transfer are an appropriate JILA activity. The recent decline in this activity is of concern and should not continue. The subpanel suggests that JILA (1) determine what industry activity at JILA should be; (2) review its current track record with quantifiable, meaningful metrics for industry connections and technology transfer over the past 4 to 6 years; and (3) put in place a plan that is appropriate to the overall JILA-NIST mission in this area.

Resources

Funding sources for the NIST Quantum Physics Division are shown in Table 5.7. Currently, the University of Colorado contributes roughly $4.7 million to JILA, the National Science Foundation contributes approximately $5.9 million, and other grants and visitor contributions total $3.8 million. This brings the total funding for JILA to approximately $20.7 million.

Staffing for the NIST Quantum Physics Division currently includes 11 full-time permanent positions, of which 9 are for technical professionals. There are also seven nonpermanent and supplemental personnel, such as postdoctoral fellows and part-time workers. Among the University of Colorado staff, there are 17 JILA Fellows.

JILA counts one Time and Frequency Division and nine QPD researchers among its Fellows and Fellow-track members, with expertise in chemistry, physics, and optoelectronics. Eight additional Fellows are members of the CU chemistry and physics faculties and seven Fellows are CU astrophysicists.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

TABLE 5.7 Sources of Funding for the NIST Quantum Physics Division (in millions of dollars), FY 1997 to FY 2000

Source of Funding

Fiscal Year

1997 (actual)

Fiscal Year

1998 (actual)

Fiscal Year

1999 (actual)

Fiscal Year

2000 (estimated)

NIST-STRS, excluding Competence

3.7

3.6

3.6

3.7

Competence

0.3

0.3

0.3

0.5

ATP

0.0

0.2

0.2

0.2

OA/NFG/CRADA

0.5

0.6

0.6

0.7

Other Reimbursable

1.1

1.2

1.1

1.2

Total

5.6

5.9

5.8

6.3

Full-time permanent staff (total)a

12

12

11

11

NOTE: Sources of funding are as described in the note accompanying Table 5.1.

a The number of full-time permanent staff is as of January of that fiscal year.

The topic of the resources necessary to maintain JILA as a center of excellence is inextricably bound to the way JILA defines itself as an institute as it contemplates the eventual departure of its astrophysical component. Two years ago, departure of the astrophysicists from JILA seemed more immediate. The subpanel is impressed with the cooperation and good will that prevail as the astrophysicists separate from the AMO-materials researchers at JILA, even as it has become clear that astrophysics is likely to inhabit the JILA site for another 10 years. The collegiality represented by this cooperation is remarkable. The subpanel remains concerned, however, about the effect of the present situation on appointments, infrastructure, and space allocations.

The subpanel's last report noted that “JILA stands today at the edge of an exciting new era. Its scientific achievements over the past few years have been outstanding and recent support of the Laboratory by NIST management has been excellent. ” This remains true today. The 1998 subpanel report ended with the observation that “now is the time to define the JILA of the future through careful discussion and planning,” and the 2000 subpanel is particularly interested in progress made toward this goal in the intervening 2 years. Some important issues arose during that time, and a number of questions posed in 1998 by this subpanel require follow-up. The subpanel found that although considerable planning and debate have surrounded the recruitment of new Fellows, rather less discussion has been devoted to larger issues at JILA, particularly a vision for the new JILA that will emerge after the departure of its astrophysics community. The subpanel urges JILA Fellows to devote time to this very important task. Such a vision will be needed for development of strategic plans to address some of the resource issues discussed in this section.

Staffing

Fellows. As noted in the section “Technical Merit and Appropriateness of Work,” the subpanel was extremely impressed by the quality of JILA's newest hires. These new Fellows and Fellow-track scientists have quickly established themselves as a vital part of the JILA community. The subpanel applauds the efforts under way to form a committee within JILA to consider recruitment of an astrophysicist with strong AMO connections. However, the subpanel is concerned that an attempt to bring in

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

such a “hybrid” appointment may require unwise compromise on the part of either the astrophysics or the AMO components of JILA, or both. Given the 10-year horizon for physical separation of the astrophysics and the AMO-materials parts of JILA, the subpanel urges caution and vigilance with regard to maintaining the collegial atmosphere and spirit of cooperation, especially in the area of appointments. The subpanel hopes that the university can find a way to speed up the physical separation of the two groups.

Other new appointments being considered also require a commitment to new resources and collaborative interactions. The scientific evolution and growth of JILA through new appointments is the sine qua non for any endeavor of this kind; nevertheless, there is a delicate balance to be struck between present capabilities and future potential that must be addressed with care. The present search for a new JILA Fellow in optical biophysics would bring the laboratory into an exciting new area, one of strong national interest. However, a new Fellow trained in biochemistry or biophysics would need access to a number of facilities and collaborators not available within JILA. Some of these are available in other departments at the University of Colorado, but bridges must be carefully built to those departments now so that a new Fellow in this area can flourish. Future appointments are also being considered in nanomaterials and molecular electronics. In this area, access to nanofabrication facilities and similar support is a must, as pointed out in the discussion of materials in the section on technical merit. The subpanel notes that although such facilities already exist at the NIST Boulder campus, they have not yet been accessed by JILA scientists. It would seem appropriate for NIST management to consider how interaction between JILA and NIST Boulder might be fostered more strongly, especially if JILA brings in a new Fellow in this area. The subpanel also recommends that JILA consider establishing a committee to liaise with several university departments (chemistry, physics, materials science, biochemistry, for example). Doing so would build both good will and the bridges that will be needed to establish successful new endeavors in optical biophysics and molecular electronics.

Staff, Students, and Postdoctoral Researchers. Members of the subpanel visited with JILA staff, senior research associates, postdoctoral scientists, and graduate students in order to learn their views of JILA. Generally, all were happy to be working at JILA. They believe that they are appreciated and able to work effectively. Although some complained about a heavy workload, even they felt that JILA is a good place to work. An important reason for this seems to be an appreciation of the teamwork among the staff and a feeling of being valued by the scientists. This climate of respect is mutual: scientists recognize that their work depends on support staff, and support staff take pride in and ownership of JILA 's scientific achievements. Students recognize the valuable support provided by staff.

Some potential issues should be noted here. First, JILA management should recognize that the staff believe their productivity has been pushed to its maximum. Staff are concerned that the quality of services they can provide to JILA might suffer from any increase in workload. This needs to be considered as JILA expands its technical programs. Second, the different cultures within the astrophysics and AMO communities regarding the length of tenure for postdoctoral research associates creates some friction for these researchers. This seems to particularly impact the astrophysics postdocs, who find that some JILA policies do not accommodate their generally longer tenure at JILA.

Management. JILA's current management structure—rotation of the JILA chair among the Fellows as a 2-year position —is well-suited to JILA's unique character. It allows the Fellows to maintain active scientific programs while assuming this leadership role. Continuity in leadership is provided by the QPD division chief, a long-term appointment. The good working relationship between the NIST and JILA managers enables a smooth-running organization.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×
Facilities

JILA faces several challenges with respect to its physical facilities. The subpanel was particularly concerned about the many complaints from Fellows, postdocs, and students about environmental control within the JILA complex. The major problem seems to be serious temperature fluctuations in the buildings over each 24-hour period. The fluctuations in temperature reduce the running time for experiments by nearly half each day, thereby reducing productivity by much more than half, since these experiments generally benefit from a momentum effect in which the amount of data collected and the results rise sharply the longer the experiment is in operation. There were also complaints about dust and vibrations. This is the premier optics laboratory in the world, a place where dust and significant temperature fluctuations simply cannot be tolerated. The university's facilities management appears to be unresponsive to the building problems. The subpanel urges NIST management to work with the University of Colorado to find a solution to the serious heating, ventilation, air conditioning, and other environmental issues that beset JILA at this time.

JILA also faces a serious space shortage that will become acute within 3 to 5 years. This will arise from the hiring of new Fellows and the expansion of the activities of recently hired Fellows, both necessary to the continued health of the institution. This situation will not be solved by the eventual departure of the astrophysics group from JILA. The astrophysics group largely occupies office space, while the most serious need at JILA in the foreseeable future is for laboratory space. Retirements, the natural way in which space was recycled in the past, do not seem likely to yield this beneficial “renewal” in the near future. This is due to the elimination of mandatory retirement as well as to the increased health and longevity of the population. In addition, attractive retirement packages frequently include an allotment of space that allows a still-vigorous retired Fellow to continue worthwhile activities. Such inducements to retire help to solve salary issues but leave JILA with an acute space shortage. The subpanel urges NIST management to work with the university to solve the space problem so that this remarkable laboratory can continue its impressive successes in the new century.

Major Observations of the Subpanel
  • JILA is a most extraordinary institution, and NIST receives enormous technical benefit from participating in it. Its international status as a center for precision metrology and interdisciplinary studies utilizing the interaction between light and matter is unrivaled. The subpanel finds that JILA has made excellent hires in the past 3 years; these newcomers have already set new directions for JILA, while contributing to the research directions of more senior staff. JILA's strength derives from the unprecedented number of important collaborations among the Fellows: these were found to be lively and growing.

  • The already world-leading excellence of JILA continues to grow, thanks to the confluence of key elements of success. The partnership between CU and NIST; the synergy, creativity, and vigor of JILA's researchers; adequate and flexible funding; superb technical support; inspired management; and the physical proximity of the researchers all serve to promote multiple cross-disciplinary collaborations. The subpanel observes that JILA's high level of excellence would be made vulnerable by a decline in any of these elements of success.

  • NIST and CU have made outstanding new appointments to the roster of JILA Fellows, laying the foundation for a rapid expansion of JILA 's already frontier-shattering achievements. The subpanel applauds the search and hiring process, which has been carried out with great wisdom, vigilance, and care. Two additional NIST Fellows in new disciplines will be added in the near future, and other new

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×

appointees will replace retiring Fellows over the next 5 to 10 years. The subpanel is confident that future searches will be as careful as those of the past few years. It recommends that as new Fellows with interdisciplinary research programs are hired—for example, in nanotechnology and optical biology—new partnerships be built and nurtured within NIST and between NIST and CU. These partnerships might include new collaborations and shared laboratories, giving a critical mass of researchers and access to necessary resources (expertise, equipment, and facilities) for the new Fellows, thus ensuring the success of their research programs.

  • The continued excellence of JILA depends on sufficient laboratory space of appropriate quality and quantity to allow the programs of the newly hired Fellows to grow and to accommodate future Fellows. The subpanel finds that such space is not readily available in the JILA building. The subpanel also finds that upgrades to existing laboratories will be vital to remedy severe problems with temperature control, dust, and vibration that interfere with experimental progress. NIST and CU are urged to find ways (e.g., new construction and/or remodeling) to solve these problems.

  • The plans for the future of JILA presented 2 years ago are being reshaped since the CU astrophysics Fellows will remain part of JILA for the foreseeable future. This evolution is appropriate and necessitates careful planning to optimize the ties between the two technical communities within JILA. It is essential that the JILA Fellows continue to work on a comprehensive, long-term strategic vision for the institute.

  • The interdisciplinary, collaborative character of JILA is its hallmark. As JILA's technical focus evolves away from its original mission of laboratory astrophysics, strong ties to all of the CU academic departments with which it is most closely allied—chemistry, physics, astrophysics, electrical engineering—are of vital importance. The subpanel finds that these ties are receiving renewed attention, and it encourages JILA to continue to place high priority on strengthening them.

Suggested Citation:"Physics Laboratory." National Research Council. 2000. An Assessment of the National Institute of Standards and Technology Measurement and Standards Laboratories: Fiscal Year 2000. Washington, DC: The National Academies Press. doi: 10.17226/9979.
×
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