Chapter 5

Physics Laboratory



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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 Chapter 5 Physics Laboratory

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 PANEL MEMBERS David H. Auston, Rice University, Chair Thomas M. Baer, Arcturus Engineering, Inc. Anthony J. Berejka, Consultant, Huntington, N.Y. Shirley Chiang, University of California, Davis Gregory R. Choppin, Florida State University Stuart B. Crampton, Williams College Leonard S. Cutler, Hewlett-Packard Company Paul M. DeLuca, Jr., University of Wisconsin–Madison Harold Metcalf, State University of New York, Stony Brook David W. Pratt, University of Pittsburgh David A. Shirley, Lawrence Berkeley National Laboratory (retired) Winthrop W. Smith, University of Connecticut Arthur W. Springsteen, Labsphere, Inc. Robert G. Wheeler, Yale University Stephen M. Younger, Los Alamos National Laboratory Submitted for the panel by its Chair, David H. Auston, this assessment of the fiscal year 1998 activities of the Physics Laboratory is based on site visits to the laboratory by the panel on March 5–6, 1998, and the annual report of the laboratory.

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 LABORATORY-LEVEL REVIEW Laboratory Mission The mission of the NIST Physics Laboratory, as stated in its annual report, 1 is to support U.S. industry by providing measurement services and research for electronic, optical, and radiation technologies. The laboratory's mission, though broad, is consistent with the overall mission of NIST. The laboratory develops, maintains, and disseminates the national standards for optical and ionizing radiation, time and frequency, and radiation temperature. The programs carried out in pursuit of this mission are generally quite appropriate and well targeted. Technical Merit and Appropriateness of Work The technical merit of the ongoing programs in the Physics Laboratory is very high, and many of the laboratory's efforts are at or define the state of the art in their field. For example, the upgrade of the laboratory's Synchrotron Ultraviolet Radiation Facility (SURF) will give NIST the premier absolute broadband radiometric source covering the far infrared through the extreme ultraviolet (EUV) regions of the electromagnetic spectrum. The laboratory continues to push the state of the art in mid- and far-infrared molecular spectroscopy for chemical and biological applications. The Time and Frequency Program at NIST is one of the best, if not the best, in the world. And NIST researcher Dr. William Phillips shared the 1997 Nobel Prize in Physics with two other scientists for his work in developing laser cooling and trapping of atoms. Further examples of the laboratory 's work are found in the divisional reviews below. The laboratory's work in databases merits special mention here. The Physics Laboratory maintains large databases of fundamental atomic and molecular properties, including atomic energy levels, transition probabilities, and emission and absorption wavelengths. These databases are essential to developing and modeling industrial processes and to understanding the earth 's environment and in many other applications. These data compilations are among the publications most often referenced in the technical literature. They are important national resources that have required decades of focused effort to develop. The panel was very impressed with the laboratory's new Web page of the Fundamental Constants Data Center. This page provides in-depth information on the fundamental physical constants, the International System of Units, and the expression of uncertainty in measurement. The searchable, user-friendly nature of the information related to the constants is especially noteworthy and should make this one of NIST's most visited sites. Because the fundamental constants are at the foundation of all of science and technology, periodically providing the scientific and technical communities with the best values available is of great importance and a critical responsibility of the Physics Laboratory. The panel was thus pleased to see that the laboratory will be completing the new Committee on Data for Science and Technology (CODATA) adjustment of the values of the constants by the end of 1998. This new, up-to-date 1   U.S. Department of Commerce, Technology Administration, National Institute of Standards and Technology, Physics Laboratory: Annual Report 1997, National Institute of Standards and Technology, Gaithersburg, Md., 1998.

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 set of values is sorely needed because there have been many improvements in experiment and theory in the last decade or so and the 1986 CODATA set, the most recent available, is badly out-of-date. A great deal of computer automation has been incorporated into the new adjustment, allowing CODATA to provide a new set of values at least every 4 years, or as often as every 2 years if new data warrant it. In the panel 's view, the initial overhead costs in time and effort of developing the extensive computer programs that will allow this significantly increased frequency is well worth it; 12 years between adjustments is unacceptable at a time when users rightfully expect new information to be immediately available. The panel was glad to see that such a long interval between updates is not likely to occur again. This worthy goal of updating the database of fundamental constants every several years will require a continuous effort—it cannot be done unless staff are allowed the time to keep fully up-to-date with the relevant experimental measurements and theoretical calculations reported between adjustments. Even after the 1998 adjustment is completed, resources must be provided so staff members can devote time to keeping current on all relevant new developments, maintain the bibliographic database on the constants, and contribute to the advancement of the field, for example, by developing and maintaining an online database on precise hydrogenic energy levels relevant to determinations of the Rydberg constant. As mentioned previously, the programs that the laboratory is engaged in are generally quite appropriate. It was not clear to the panel whether program priorities had been chosen based first on industry needs, rather than on laboratory capabilities. When asked, the laboratory produced a list of programs that had responded rapidly to specific industry requests, indicating that the laboratory can and does redirect its efforts toward specific industrial needs when they arise. Impact of Programs Although not every program is equally successful, overall the laboratory has an impressive record of impact on specific industrial needs. Details on impact are given in each divisional report below, but a few items are highlighted here as examples. Downloads from the laboratory's database Web site have been growing exponentially, and the number of pages delivered to customers from the Web site increased from 32,000 to 64,000 per month over the last year. This site includes physical constants, atomic and molecular spectroscopic data, ionization data, x-ray and gamma-ray data, nuclear and condensed matter physics data, and other NIST data. Users of these data span the spectrum from university students to industrial researchers, and the data 's availability provides a major infrastructural support to science and technology in related areas. For example, wavelength measurements of rare-earth metal spectra are used by the lighting industry in designing more energy efficient products with better color balance. The laboratory provides standards and measurement quality assurances to the lighting, photographic, automotive, xerographic, and electronics industries, among others. State-of-the-art spectroscopic research will provide new and improved standards and calibration services for industry. Through its Council on Ionizing Radiation Measurements and Standards (CIRMS), and Council for Optical Radiation Measurements, the laboratory receives industry input on measurement and standards needs in those areas.

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 Laboratory Resources Funding sources2 for the Physics Laboratory (in millions of dollars) are as follows:   Fiscal Year 1997 Fiscal Year 1998 (estimated) NIST-STRS, excluding Competence 29.8 31.4 Competence 2.9 1.9 ATP 0.8 1.6 MEP 0.0 0.0 Measurement Services (SRM production) 0.3 0.3 OA/NFG/CRADA 9.6 9.7 Other Reimbursable 3.4 3.4 Total 46.8 48.3 Staffing for the Physics Laboratory currently includes 207 full-time permanent positions, of which 174 are for technical professionals. There are also 56 nonpermanent and supplemental personnel, such as postdoctoral fellows and part-time workers. The laboratory's programs still suffer from the deterioration in physical plant described in the panel's previous report. For example, rainstorms create leaks in offices and laboratories, and there is seepage in the below-grade vaults used to house accelerators in the Radiation Physics Building. Scientists are forced to spend time and effort on expensive work-arounds to obtain the temperature control, humidity control, vibration control, and cleanliness that are necessary for their high-precision measurements. This diversion of time and resources should not be necessary at a world-class institution like NIST. NIST has developed a Facilities Improvement Plan that, if funded and implemented, would greatly relieve the conditions described. The panel was pleased to learn that the laboratory has a succession plan in place to ensure its continued international leadership in fundamental constants. Updated values of these present constants are free to users, and this is indeed a most valuable aspect of this service. It enables multiple-student access, encourages browsing, and otherwise provides a valuable asset to the scientific and technical community in government, industry, hospitals, universities, and other 2   The NIST Measurement and Standards Laboratories funding 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 it is allotted 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. Manufacturing Extension Partnership (MEP) funding reflects support from NIST's MEP for work done at the NIST laboratories in collaboration with or support of MEP activities. Funding to support production of Standard Reference Materials 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.

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 technologically oriented enterprises. Although the imposition of user fees to recover some of the costs of this service might permit some expansion and strengthening of the service, they would have a negative impact on its current broad dissemination, especially to students and young scientists. DIVISIONAL REVIEWS Electron and Optical Physics Division Mission The Electron and Optical Physics Division's mission is to develop measurement capabilities needed by emerging electronic and optical technologies, particularly those required for submicron fabrication and analysis. In pursuit of its mission, the division maintains an array of research, measurements, and calibration activities. It provides the central national basis for absolute radiometry in the far ultraviolet and EUV regions of the electromagnetic spectrum, maintains specialized facilities for scanning electron microscopy with polarization analysis and scanning tunneling microscopy (STM), maintains an EUV optics characterization facility, and performs theoretical and experimental research in atomic and condensed matter physics in support of its basic mission objectives. The division has specific programs to develop techniques for the following purposes: determining magnetic microstructures; establishing the physical and chemical basis of device fabrication on the atomic scale; producing and characterizing artifacts with atomic-scale quality control; maintaining expertise in physical and applied optics in the 10 to 100 nm wavelength range; maintaining the national radiometric standard in the 2 to 250 nm wavelength range; and delivering quality measurement, calibration, and secondary standards services in the 2 to 50 nm wavelength range. These programs clearly conform to the division mission stated above. The division programs also support the Physics Laboratory mission and NIST mission. The division has specific examples of supporting U.S. industry directly, in addition to performing extremely high-quality research that anticipates industrial measurement standards and needs. The division's mission statement fails to include the division's efforts to provide measurement support for existing technologies. The division could consider correcting this oversight. Technical Merit and Appropriateness of Work The division's Photon Physics Group has continued its leadership role in the development of new technology in the EUV and x-ray regions of the electromagnetic spectrum and in the application of this technology to basic and applied research. The group's primary focus has been developing instrumentation to complement the unique capabilities of the SURF II synchrotron light source, which allows application of this source to a variety of problems in metrology. In particular, the group has made substantial progress in developing thin film coating techniques for

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 the EUV and x-ray regions of the spectrum. Their approach utilizes nontraditional thin film materials, for example, molybdenum/silicon, that are necessary to withstand the large photon energies at these short wavelengths. The group has developed a unique thin film coater, combining electron beam deposition of films with ion milling, to achieve ultraprecise levels of surface flatness and surface roughness on optical surfaces. The group has already achieved x-ray reflectivities on its optics that exceed 50 percent at normal incidence. This achievement will allow the construction of a number of important x-ray microscope devices with applications in microelectronics and biotechnology. As a spin-off of this program, the group has measured and published the indices of refraction for the coating materials used in this spectral region (B4C, C, Mo, Si, and W), which is a critical part of developing x-ray optical coating technology. The group has used their expertise in x-ray optics to help develop tomographic techniques that allow three-dimensional measurements of submicron features in integrated circuits. They have demonstrated spatial resolution down to 100 nm. This research has direct applications in the metrology of submicron structures that are a critical part of next-generation integrated circuits. The Photon Physics Group has continued its efforts in far UV metrology by successfully concluding a several-year effort to measure the 1S to 2S transition in atomic He using high-precision, Doppler-free, two-photon laser spectroscopy. This result provides a benchmark challenging the accuracy level of current theoretical calculations of quantum electrodynamic effects such as the Lamb shift and the electron-electron correlation correction to the atomic levels in neutral He. The Far Ultraviolet Physics Group's upgrade of the SURF from SURF II to SURF III is proceeding smoothly. SURF II was closed and dismantled in late 1997. With continued progress on the current schedule, SURF III should be operational in the fall of 1998. The new SURF III facility will provide a world-class, absolute radiometric capability. The magnet pole faces and other critical surfaces are planar to ±0.001 in., permitting very high magnetic field uniformity. The other parameters for assuring accurate absolute radiometric standards measurements are also in place. In addition, the projected higher electron energy will increase the accessible photon energy, allowing the study of organic and biological materials. SURF III will be the world's premier absolute broadband radiometric source in the far infrared through the EUV regions of the electromagnetic spectrum. This is of great value for both science and industry. The Electron Physics Group is a world leader in high-resolution imaging of magnetic materials, both by STM and scanning electron microscopy with polarization analysis (SEMPA). Staff have developed spectroscopic techniques for elemental identification of iron and chromium metal atoms with atomic resolution in magnetic surface structures. The group has also developed novel fabrication methods for nanowires and nanotrenches by reactive-ion etching of laser-focused chromium. Such chromium lines have also been used as a self-shadowing mask for deposition of nanoscale magnetic wires of iron. In addition, the group has excellent theorists who work with the experimentalists on understanding of giant magnetoresistance (GMR) effects in thin magnetic films. Another recent accomplishment relates the measurement of the magnetic exchange coupling in Fe/Au/Fe(100) sandwich structures using a unique confocal magneto-optical microscope to the atomic scale roughness of the films measured with reflection high-energy electron diffraction. The new Nanoscale Physics Facility will be state of the art when it is completed at the end of 1998. The facility will be used to elucidate the physics of electron confinement and transport in nanoscale structures and devices, such as two-dimensional electron gases, quantum wires and

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 dots, and magneto-transport devices. 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 system is also equipped with molecular beam epitaxy fabrication of metal and semiconductor devices, with in-vacuum transfer of fabricated samples among the chambers. Measurements will be performed with both atomic-scale positional resolution and high-resolution of electronic state spectroscopic features. The group has also been collaborating with the NIST Electronics and Electrical Engineering Laboratory (EEEL) on quantitative comparisons between various magnetic imaging techniques. The EEEL has fabricated a magnetic imaging test sample from thin film high-density magnetic recording media with a test pattern and lithographically patterned navigation marks to allow repeated measurements of the same area of the sample. Quantitative magnetization information from the Electron Physics Group's SEMPA technique will be compared with information about the magnetic contrast observed in magnetic force microscopy images measured by many other groups. The group's significant efforts in characterization of magnetic thin films and in fabrication of nanowire structures are both extremely important to U.S. industry in magnetic storage technology and next-generation integrated circuit manufacturing. Future research directions on magnetic exchange coupling strengths of antiferromagnets, metastable atom lithography, and the use of laser-focused chromium lines as a nanoscale length standard build on successful work of the group and are completely in accordance with the division, laboratory, and NIST missions. Impact of Programs The operation of SURF II has supported the measurement and calibration services and research efforts of the division, as well as other NIST units and external customers. A dedicated reflectometer system on Beam Line-7 at SURF II has been used to determine reflectivities of multilayer optics in the EUV, as well as grating efficiencies and film dosimetry. Over 60 samples from industry, other government laboratories, and universities were analyzed in 1997 (this number is lower than in previous years because of the SURF II shutdown). The spectrometer calibration service on BL-2 supports NASA programs in solar physics and EUV astronomy. BL-9 and a new dual grating monochromator on BL-2 are used for UV and EUV detector transfer standards. The Electron Physics Group has a notable history of working directly with many different companies on magnetic characterization of samples by SEMPA. The problems analyzed for various companies included the following: noise behavior in hard disk recording media for Seagate Magnetics; domain motion and structure of magnetic recording heads for Digital Equipment Corporation; magnetic configuration of magnetic random access memory cell for Nonvolatile Electronics, which led to the solution of a 2-year-old dynamic switching problem; measuring pinning sites leading to energy losses in amorphous magnet transformer material for AlliedSignal; and planning collaborations on magnetic microstructure problems for the National Storage Industry Consortium.

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 Resources Funding sources for the Electron and Optical Physics Division (in millions of dollars) are presented below:   Fiscal Year 1997 Fiscal Year 1998 (estimated) NIST-STRS, excluding Competence 4.7 5.0 ATP 0.1 0.2 OA/NFG/CRADA 0.8 0.5 Other Reimbursable 0.1 0.1 Total 5.7 5.8 Staffing for the Electron and Optical Physics Division currently includes 27 full-time permanent positions, of which 24 are for technical professionals. There are also eight nonpermanent and supplemental personnel, such as postdoctoral fellows and part-time workers. Atomic Physics Division Mission 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. The division's mission statement fails to include its work in standards and databases for atomic quantities. This is an omission that might merit consideration. Technical Merit and Appropriateness of Work The Atomic Physics Division continues to be an international center of excellence in atomic and plasma physics. The core of this division 's work is new measurement methods, spectroscopic standards, and reference data. Its several groups have earned the respect of the entire community, and one of its researchers was awarded the 1997 Nobel Prize in Physics. The very detailed theoretical work on quantum dots and other microscopic structures in the Quantum Processes Group is promising for both physics and applications. Their theoretical work on ultracold collisions is closely related to the laser cooling and trapping experimental work for which the Nobel Prize was awarded. It is appropriate that a new staff member has just been added to this group. The Atomic Spectroscopy Group does research in obtaining atomic spectral data in the optical region for neutral and ionized atoms and provides published data compilations of critically evaluated atomic energy level and wavelength data. Two different approaches are used in data

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 compilation: First, measurements or calculations of fundamental atomic data made by researchers worldwide are collected and critically evaluated for accuracy and reliability. Second, the Atomic Spectroscopy Group maintains unique experimental facilities to directly measure fundamental properties. One highlight of the laboratory research of this group is the new Fourier transform (FT) spectrometer that is now operational and that has produced new wavelength measurements of the rare-earth spectra of dysprosium I and dysprosium II. This research is supported by the Electric Power Research Institute, a research consortium serving the lighting industry. Rare earth additives to be used, for example, in stadium lamps, are being investigated for greater efficiency and better color balance. This is significant, since commercial lighting represents about 20 percent of all U.S. electric power consumption. The laboratory is also providing atomic data needed to develop new, mercury-free, fluorescent lighting systems that will be more efficient and reduce mercury pollution from discarded lamps. With the kind of data provided by the Atomic Spectroscopy Group at NIST, modeling can replace increasingly expensive and time-consuming empirical testing. Current efforts are aimed at providing data to help manufacturers model ways to improve lighting efficiency by as much as a factor of two. The use of these data should increase in the future as large-scale numerical simulation is taken up by more and more industrial and scientific users. At present there are about 10 personal requests for these data per week. In the fall of 1997, the division sponsored a major international conference on atomic and molecular data and their applications with the division chief as the principal organizer. The Gaseous Electronics Conference plasma reference cell developed by the Plasma Radiation Group uses optical, radio-frequency, and electrical probes to determine and standardize measurement of plasma properties, particularly for industrial uses such as plasma etching of semiconductor wafers. The group recently developed a plasma oscillation probe for measuring electron densities. This new method compares favorably with the more standard Langmuir probe measurements. The electron beam ion trap now in operation in this group for the study of spectra and interactions of highly ionized species is used in both pure science (e.g., atomic lifetimes) and applications (e.g., surface modifications using highly charged ions). This new facility has been further upgraded with the addition of an ultrahigh vacuum in situ scanning tunneling/atomic force microscope for studying the effect of the interaction of ions of charge q>>30+ with silicon wafers and other surfaces. This will permit direct observation of nanoscale surface modifications by the ions without removing the sample from the vacuum, greatly extending the value of the existing diagnostics using x-ray and electron spectrometers. Last year's report described the Laser Cooling and Trapping Group as one of the world's leaders in this very new and rapidly developing field of atomic physics, and this year the accolade was corroborated by the award of the Nobel Prize to the group's leader. This is the highest award a scientist can achieve, and the honoree, William D. Phillips, is not only the first NIST employee to be so honored, but also the first U.S. government employee to receive the physics prize. The subject of laser cooling and trapping of atoms is broader than the name suggests and, in fact, could be called “optical manipulation ” of neutral atoms, which includes laser cooling and many other subjects. The group had several times set the record for the lowest temperature ever achieved and had set its sights on more general topics. In many cases, these studies lead further in

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 the direction of improved high-resolution spectroscopy, better atomic clocks, more atomic collision information, and further application toward atom optics. Another area of considerable achievement comes from the ultracold collisions. The precision spectroscopy of the vibrational levels has led to a vastly improved value of the dipole moment and hence of the lifetime of the 32p state of Na. This is probably one of the most accurate measurements of the lifetime of an atomic excited state. This new form of high-resolution spectroscopy is so sensitive that the experimenters can measure the effects of retardation on the resonant dipole-dipole interaction. The recent merger of the Quantum Metrology Group into the Atomic Physics Division appears to be successful. The new Displacement Measurement Competence project in this group utilizes a triad of interferometric methods—Fabry-Perot, Michelson, and x-ray interferometry—to establish a new standard of accuracy in distance measurements over a sizable fraction of a meter. Among the possible applications would be the location (relative to a reference point) of another point on a very large silicon wafer. A dynamic new team for subnanometer-scale motion measurement has been assembled in the last year, including collaborators from the NIST Manufacturing Engineering Laboratory. This Competence project has materially strengthened the Quantum Metrology Program. This is an extremely ambitious program and has the potential for very high payoff. Precision gamma-ray measurements on the joint NIST-Institute Laue Langevin Guide to Available Mathematical Software (GAMS-4) spectrometer, in combination with accurate nuclear mass differences, have provided new determinations of the neutron mass and the molar Planck constant. In a low-cost electron-spin resonance study of hydrogen impurities in one silicon sample, a discrepancy of 3 ppm in the density has been resolved. This explains the “molar volume anomaly” that has been a problem since 1994 in the group's attempt to establish a new atomic-based standard of mass, the “silicon kilogram,” to replace the artifact platinum-iridium standard kilogram housed in Paris, which is the basis for worldwide realization of the mass standard. Replacement of this artifact by an atomic-based standard should substantially reduce the drift in mass experienced by national standards worldwide. Impact The division continues to be responsible for three Atomic Data Centers: the Atomic Energy Levels Data Center, the Data Center on Atomic Transition Probabilities and Line Shapes, and the Data Center on X-ray Transition Energies and Wavelengths. Much of this information is being furnished and coordinated in a user-friendly way on the Internet through cooperative efforts with the laboratory's Electronic Commerce in Scientific and Engineering Data Office. To improve dissemination of the NIST databases, the Physics Laboratory has developed (in the past 3 years) a freely accessible Internet Web site with a growing number of data compilations. More than 100,000 database hits are made each month, with the number of downloads growing exponentially. The number of hits on the databases increased by a factor of 3 in 1 year, from 35,000 to 100,000 per month. It is noteworthy that SEMATECH/Lincoln Laboratory came to the Plasma Radiation Group in this division for help with precision measurements of deep UV optical constants of

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 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, is based on a meeting of the Subpanel for JILA in Boulder, Colorado, on January 29–30, 1998, and on documents provided by the institute. 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 F. Fleming Crim, University of Wisconsin –Madison, Chair; A. Paul Alivasatos, University of California, Berkeley; Robert W. Field, Massachusetts Institute of Technology; George W. Flynn, Columbia University; E. Norval Fortson, University of Washington; Frances A. Houle, IBM Corporation; H. Jeffrey Kimble, California Institute of Technology; Margaret M. Murnane, University of Michigan; Steven S. Vogt, University of California Observatories/Lick Observatory; and Carl A. Zanoni, Zygo Corporation. Mission According to JILA personnel, the mission of the NIST Quantum Physics Division 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 performs the following tasks: Develops the laser as a precise measurement tool, Determines fundamental constants and tests the fundamental postulates of physics, Exploits Bose-Einstein condensation (BEC) for metrology and low-temperature physics, Devises new ways to direct and control atoms and molecules, and Characterizes chemical processes and their interactions with nanostructures. The division's efforts in precision measurement, laser stabilization, BEC, control of atoms and molecules, and the characterization of chemical processes are all closely aligned with the needs of NIST and the execution of the NIST mission. The measurements and standards program promotes the U.S. economy and public welfare by providing technical leadership for the national measurement and standards infrastructure and by assuring the availability of essential reference data and measurement capabilities. The Quantum Physics Division has a proper understanding of its role within NIST and performs its functions well. The mission statement does not include astrophysics research among its goals because the NIST Quantum Physics Division no longer supports the Astrophysics Fellows and activities in JILA. During the site visit, the panel learned that the institute has begun planning for the possible departure of the Astrophysics Fellows from JILA to other homes within the University of Colorado. The Resources section discusses important issues related to this transformation.

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 Technical Merit and Appropriateness of Work The technical merit of the work at JILA is superb and is on par with the best in the world. In the subpanel's view, the accomplishments and plans of JILA represent the result of the formation of a “cluster of excellence.” The connection among most of the programs is real and strong, and such associations enhance each project and produce collaborations that make JILA unique. Precision measurement and metrology has unified and enlivened a wide range of work at JILA throughout its history. This research continues to span a broad spectrum, from measurements of parity nonconservation in atomic physics to progress in laser stabilization and optical frequency standards to the absolute determination of the Newtonian constant of gravitation. A principal unifying theme remains the development of new measurement techniques based on the considerable expertise in optical physics at JILA. One example out of many is the invention at JILA of the Pound-Drever-Hall technique for laser stabilization, which has become an essential tool throughout laser-based science. A recent achievement that also resulted from the unique expertise available at JILA is the remarkably precise measurement of parity nonconservation in the cesium atom, completed just this past year. In this work, a small-scale experiment probes fundamental electroweak physics well beyond the energies available at the largest high-energy accelerators. To describe and assess the merit and accomplishments of the programs at JILA, the subpanel has provided some introductory comments and two illustrative examples followed by more systematic descriptions of the five areas of activity at JILA. The intention is to illustrate the excellence of the organization, briefly document some accomplishments, assess the appropriateness of the programs, and anticipate future opportunities and challenges. A Cluster of Excellence From the perspective of the external scientific community as embodied by the subpanel, JILA is more than a collection of outstanding scientists. It is a national resource that has time and again created enabling capabilities for the benefit of the scientific enterprise. By way of diverse associations among the Fellows, JILA has influenced the advance of science and technology profoundly, especially with respect to the development of technical tools and their generous dissemination. In fact, enlightened self-interest may account for the broad base of support that JILA enjoys in the scientific community, even in the face of generally diminishing funding for basic research. The subpanel sees the long-standing programs in precision measurement and metrology as essential forces in creating the high standing and impact of JILA. Long-term, stable support and JILA's unique infrastructure not only have produced spectacular scientific advances but also have driven the development of technical tools that help fulfill the mission of NIST and enable research across the nation and the world. The broad-based practical consequences and high-quality science growing out of the cluster of excellence at JILA are a theme of this report. Illustrative Examples. There are many examples of the integration of expertise from different areas leading to dramatic and important scientific and technical advances at JILA. The 1996 report, for example, emphasized the first laboratory observation of BEC. In this year's assessment, the subpanel has chosen to describe briefly two examples that illustrate connections among precision measurement, optics, and chemical physics expertise that have created

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 approaches and devices that enable advances in fundamental science and technology. These two advances, a new spectroscopic technique and a new radical source, happened largely because of the proximity of scientists with complementary expertise working within the cooperative environment of JILA. The Noise-Immune Cavity-Enhanced Optical Heterodyne Molecular Spectroscopy (NICE-OHMS) technique is a product of 30 years of tool making by a JILA Fellow. NICE-OHMS has achieved a world-record fractional absorption of 1 part in 1013 (at sub-Doppler resolution). NICE-OHMS will have many applications in spectroscopy, studies of intramolecular dynamics, and detection of trace species. It combines a stabilized cavity, an ultrastable scanned laser, and frequency modulation (FM), all techniques pioneered at JILA. In 1969, a saturation dip in methane (CH4) was used to create an ultrastable laser at 3.39 µm. The year 1979 brought the invention of the FM technique, wherein a radio-frequency-driven electro-optic modulator creates a matched pair of oppositely phased sidebands on the laser frequency. These sidebands provide a basis for many optical tricks, from locking the longitudinal mode of a cavity to a laser frequency, to shot-noise-limited detection of differential absorption between the two sidebands. By introducing the frequency-modulated beam into a cavity, where the cavity length is locked to the laser center frequency and the radio-frequency offset of the sidebands is locked to the free spectral range of the cavity, one obtains the most sensitive absorption spectrometer in existence. Because molecules are subjected to two counterpropagating beams of radiation, a sub-Doppler saturation dip lineshape results, much like that employed in the CH4 stabilized 3.39-µm laser from 30 years earlier. NICE-OHMS, by advancing the limits of resolution at ultrahigh sensitivity by several orders of magnitude, will have an enormous impact on chemical physics (and forensics), although it is currently impossible to predict the specific directions and discoveries that will result from this advancement. The pulsed slit jet radical source is a new development that provides a way of forming an intense, translationally cold beam of radicals. The relatively long slit (5 cm) provides a good absorption path and reduces transverse Doppler broadening, making the technique ideal for both ultrahigh-resolution absorption spectroscopy and for generation of femtosecond pulses of x rays by harmonic generation. When the work that would lead to this breakthrough began in 1984, the primary goal was to build the best possible source for high-resolution absorption spectroscopy of van der Waals cluster molecules. With the substantial involvement of the JILA machine shop in design and fabrication, the first pulsed slit jet absorption spectrum was published within a year. Many laboratories all over the world are now using pulsed slit jets, built from the latest machine drawings out of JILA in order to do absorption spectroscopic studies of a wide variety of systems. Most recently, by striking a discharge inside the slit jet, JILA scientists have built the best and most versatile source of ions, radicals, and cluster ions. In typical JILA fashion, another group at the institute has adapted a 1 kHz pulsed slit jet to obtain a gas-phase harmonic generation scheme that will soon provide a tabletop source of femtosecond x-ray pulses. The unique JILA combination of chemical physics and nonlinear optics expertise continues to provide major technological advances in totally unpredictable areas. Assessment of Research Areas. The cases described above are only two examples of the high-quality work performed at JILA. In the following sections, the subpanel discusses five broad areas of research: fundamental and precision measurements, optical and nonlinear optical physics,

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 materials interactions and characterization, atomic and molecular interactions and chemical physics, and astrophysics. Fundamental and Precision Measurements. The first BEC in a gas was observed at JILA in the spring of 1995 using trapped rubidium (Rb) atoms. This accomplishment became the centerpiece of the 1996 subpanel assessment. Two years later, the extent of new research launched by this discovery is evident. Eight groups worldwide have observed BEC in atom traps, many more groups are actively trying to see BEC, and journals are filled with reports from theoretical groups now working in the field. Potential applications of BEC, such as atom lasers, are widely discussed and are under active study at JILA and elsewhere. In recent JILA research, the BEC group elucidated the fundamental thermodynamics and coherence properties of the condensates and observed a type of quantum beat note in the first mixed species condensates (using different spin states of 87Rb) that is reminiscent of the Josephson junction in superconductivity. Just 1 year after the BEC discovery, a different JILA experiment made big news, again reaching far beyond the realm of atomic physics. After 10 years of effort, JILA scientists completed a measurement of atomic parity nonconservation in the cesium atom, accurate to 0.35 percent. This is a truly remarkable achievement in high-precision atomic physics. This table-top experiment probes the nuclear and elementary particle physics frontier and tests the existence of particles that are too heavy to be created in the highest energy accelerators now available. In the domain of atomic physics itself, the cesium parity nonconservation results are likely to stimulate advances in atomic theory and spectroscopic studies to improve on the current cesium calculations. This experiment exemplifies the standards of precision and technological innovation that are hallmarks of JILA. The unification of science and technology at JILA can also produce commercial benefits. An example is the development of ultralow-loss mirrors, which produce over 50,000 reflections. These mirrors were perfected by JILA scientists in collaboration with Research Electro-Optics, Inc., and have become the industry and commercial standard. Basic metrology remains a strong program at JILA, and research in laser stabilization and optical standards continues to advance. An infrared laser based on Nd:YAG was locked to a narrow molecular line of iodine and attained unprecedented laser stability of 5 × 1015, by far the best achieved worldwide. In the subpanel's view, the coupling between such precision work and the other areas of research at JILA sets this institute apart. The strength in fundamental metrology, especially in optics and lasers, is the bedrock of JILA, and no other U.S. program could produce the sort of innovations that come out of JILA. Optical and Nonlinear Optical Physics. The optical science and technology effort at JILA is excellent. The work fits well in the mission of NIST, in that it has strong potential impact on industry and will also lead to the development of new measurement techniques and standards. In addition to performing fundamental and applied research in optics, the institute scientists provide essential enabling technology for precision measurement work at JILA and beyond. For example, the development of the atom hose, in which light beams guide atoms through fibers, promises to be the basis of atom interferometers. A major success story in the area of nonlinear optics is the development and characterization of fiber sensors and photorefractive materials and devices. These very robust sensors tolerate hostile environments and, thus, have wide application in industry. JILA is now testing such sensors for robotics and automobile engine diagnostic

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 applications. Only by understanding the precise, fundamental interaction of light and matter, and the behavior of novel materials under external stresses, could scientists develop these new generation probes. The creation of these fiber sensors and photorefractive materials is an example of the ability of JILA to take ideas from the research laboratory into real-world industrial applications. JILA has recently added two new staff members in ultrafast optics and applications of ultrafast pulses to materials science. Ultrafast optics is a rapidly growing field with a host of scientific opportunities and challenges, and JILA is positioning itself to be a leader and national resource in this area. Ultrafast optics is a very appropriate area of investigation for JILA because precise knowledge of nonlinear optical constants of materials, of how to characterize ultrashort pulses accurately, and of the interaction of short pulses with materials has consequences in areas as diverse as micromachining, laser surgery, nonlinear microscopies, optical communications, and future laser-based high-energy electron and photon sources. Precise measurements of nonlinear pulse propagation in materials are already under way, adding much-needed understanding to ultrafast nonlinear dynamics. Finally, workers at JILA are using new nonlinear optical techniques to generate coherent light throughout the visible and x-ray regions, and such sources will have a great impact on the materials science and chemical physics efforts at JILA. There is a strong potential for these efforts in nonlinear optical techniques to duplicate the great synergistic relationships between optics and precision measurements. Such associations have led to BEC and many other achievements. Materials Interactions and Characterization. Materials-related research, a relatively new part of JILA's spectrum of activities, has developed several strong themes in conformance with the expertise of the Fellows and of the newly hired Fellow-track NIST employees in optics and precision measurements. The primary focus is on development of measurement techniques rather than on synthesis of new materials or technology development. The themes fall into two groups: ultrahigh-resolution optical measurements in space and time and diagnostics for characterization of semiconductor processing reactions. In the first area, two separate experiments are developing near-field scanning optical microscopy. One uses femtosecond pulses to follow the time evolution of localized light emission from solids, and the other uses field enhancements from an atomic force microscopy tip to perform spectroscopy on single molecules. Complementary experiments being set up by the new NIST staff member use ultrafast techniques to allow the study of structure and excitation dynamics in solids and at interfaces. (This work is also mentioned in the section on Optical Science and Technology.) The primary goal of these new experimental programs is to develop methods to probe the very limits of atomic and molecular extent and temporal behavior. The diagnostics work mainly emphasizes development of high-precision spectroscopic probes to characterize the course of reaction in etching and film growth and to evaluate thin film structures. Such knowledge is vital to the successful application and optimization of industrial processes, particularly as critical dimensions shrink and demands for device performance and reliability become more stringent. The subpanel believes that the materials research program uses JILA 's strengths to build what will become a center of excellence in optical characterization of solids. The knowledge and experience gained are important resources for discovery of new physical phenomena in the condensed phase and for techniques of direct technological interest to industry. The success of the effort depends on close partnerships between groups with optics expertise and groups that can

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 produce and characterize the necessary samples. The JILA Fellows have worked to develop these partnerships, and the subpanel encourages them to continue to do so within NIST and the University of Colorado as well as with scientists at other institutions. Connections to complementary expertise are important in ensuring rapid progress in the experimental work and timely transfer of new insights into device design and process engineering. Atomic and Molecular Interactions and Chemical Physics. The group working in atomic and molecular interactions and in chemical physics uses lasers to examine the structure and dynamics of atoms, molecules, ions, radicals, and clusters in carefully designed and unique, well-specified situations. The goals of these experiments are invariably to answer basic questions or to demonstrate the ability to exert microscopic control over intramolecular dynamics of a type qualitatively different from what has been feasible, understood, or even imaginable before. Several examples illustrate the breadth of the effort. First, new control schemes, based on crafting the amplitudes and phases of the spectral content of a femtosecond pulse, are being tested on the Li2 molecule for eventual use on more complex systems. Second, femtosecond pump-probe studies examine the detailed mechanism of solvation and caging, particularly the role of charge localization and delocalization in directing the dynamics of the solvent cage, in clusters of I2(CO2)n and I2(OCS)n. Third, a new pulsed discharge slit jet provides the best and most versatile known source for spectroscopic study of radicals, ions, and clusters. Some characteristics that make this jet so impressive are its high density, minimal collisions between reactive target species, low temperature, and long path length. Finally, pioneering work continues to explore “spectroscopy along the reaction coordinate, ” which is perhaps the most exciting incarnation of photodetachment spectroscopy, a technique whose birth coincided with that of JILA. Throughout the work in this field, each project combines, at the state of the art, at least two of the five goals stated in the Quantum Physics Division mission by developing the laser as a precise measurement tool and devising new ways to direct and control atoms and molecules. Astrophysics. There are currently eight Astrophysics Fellows at JILA, and a few adjunct Fellows are still active in this field. In recent years, the JILA goals have largely turned away from the historical mission to perform laboratory astrophysics, although the JILA Astrophysics Fellows still retain strong intellectual ties to JILA Fellows in the NIST Quantum Physics Division and in the University of Colorado physics and chemistry departments. Many scientists in JILA view this interaction as stimulating and valuable. NIST no longer supports the Astrophysics Fellows, and thus they are primarily affiliated with the University's Department of Astrophysical and Planetary Sciences. They do, however, share JILA office space and infrastructure. This arrangement, although perhaps not optimal in the long run, is currently working quite satisfactorily. The Astrophysics Group makes up a sizable fraction of JILA Fellows (8 out of 21) and brings substantial overhead through research grants. JILA Fellows working in astrophysics are likely to be known within their community as individuals rather than as members of a larger JILA team. In fact, many scientists in the astrophysical community are not even aware that JILA also houses research chemists and physicists. Scientific research published by JILA Astrophysics Fellows is world class and highly regarded in the astrophysics community. The research appears in the most prestigious, peer-reviewed journals and spans a wide range of topics, from complex numerical simulations and theoretical modeling of magnetohydrodynamic processes in the Sun and in interstellar space to

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 detailed modeling of supernovae and energetic compact objects. For example, research by astrophysicists at JILA led to a detailed seismological probing of the interior structure of the Sun. JILA scientists are also engaged in pursuing basic questions in cosmology, through studies ranging from surveying distortions in large-scale red-shift surveys of galaxies to measuring actual fossil relics of the nucleosynthesis processes that occurred in the first few minutes of the life of the universe. Astrophysicists at JILA are aggressive and successful participants in instrumentation missions for NASA, including the Goddard high-resolution spectrometer (GHRS) and the space telescope imaging spectrograph for the Hubble Space Telescope (HST). They are also involved with instruments for other upcoming NASA missions such as the Far Ultraviolet Spectroscopic Explorer, the Advanced X-ray Astrophysics Facility, and the Cosmic Origins Spectrograph. JILA astrophysicists are also involved in the design of both ground-based and space-based interferometers for the detection of gravity waves and other space-based interferometers for the detection of Earth-like planets around other stars. Such projects define some of the cutting edges of astrophysics research. Many of these pursuits push the limits of dimensional stability and time referencing and, not surprisingly, flourish in JILA's historical atmosphere of state-of-the-art measurement. The JILA environment seems quite conducive to the types of astrophysics research described above. One of many examples of the impact of the astrophysics work at JILA is the contribution made to determining whether there is sufficient matter in the universe to halt its expansion. This issue is one of the fundamental questions of modern cosmology. Because there are reliable theoretical models of the first few moments of the creation of the universe and laboratory measurements of the important atomic interactions, the application of the standard model of Big Bang nucleosynthesis predicts a deuterium to hydrogen ratio (D/H) of about 1:20,000, a ratio that is a relic of the moment of creation. A simple measurement of the primordial D/H ratio (the relative areas under two lines in a spectrum) provides a direct answer to the question of whether there is enough matter to halt the cosmic expansion. A JILA Fellow and his coworkers recently obtained D/H measurements in the local interstellar medium using the GHRS that JILA staff helped build for the HST. Taken together with other observations, these measurements will accurately trace the origin and evolution of the deuterium in the universe and thus yield the present-day density of baryonic matter. The JILA group on this project, because of its many years of development of the instrumentation and techniques for making these difficult measurements, is a key contributor to this important work. It is excellent science, of which JILA should be duly proud. Impact of Programs The JILA programs are actively and effectively disseminated through technical publications, invited talks, and the guest researcher program. During 1996 and 1997, 392 technical papers were published, permanent and visiting JILA staff members gave 243 invited talks, and 43 guest researchers worked at JILA. An especially noteworthy example of the impact of the scientific work at JILA has been the creation of eight BEC laboratories around the world subsequent to the pioneering, successful BEC work done at JILA. The work to foster industrial connections at JILA is energetic and successful. A member of the staff reserves one-half of his time for coordinating industrial activities, and JILA is

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 aggressively pursuing three initiatives to improve its involvement with industry: an industrial outreach program, the expansion of JILA 's CRADA activities, and active efforts to identify and protect JILA 's commercially valuable intellectual property and to facilitate licensing by industry. The outreach program has brought in 9 or 10 visitors from industry per year to give a talk related to industry and science and to interact with graduate students, postdoctoral researchers, and staff members. The students view this program very positively. In addition, the “Industry at JILA” program brings senior engineers and researchers from industry to JILA for 1- to 2-week visits. There are currently five CRADAs in place that provide tangible connections to industry. Over the last several years, three U.S. patents have been granted and seven more have been filed in order to protect JILA's commercializable intellectual property. A very professional site on the World Wide Web makes it easy for interested companies to learn about JILA and make inquiries. The site is an effective means of disseminating information about the intellectual property available at JILA. Since 1994, about 26 graduate or postdoctoral students from JILA have taken jobs in industry. Resources Funding sources for the NIST Quantum Physics Division (in millions of dollars) are as follows:   Fiscal Year 1997 Fiscal Year 1998 (estimated) NIST-STRS, excluding Competence 3.7 3.6 Competence 0.3 0.3 ATP 0.0 0.2 OA/NFG/CRADA 0.5 0.6 Other Reimbursable 1.1 1.1 Total 5.6 5.8 The University of Colorado contributes roughly $4.6 million, the National Science Foundation (NSF) contributes approximately $3.7 million, and other grants and visitor contributions total $4.5 million. This brings the total funding for JILA to approximately $18.6 million. Staffing for the NIST Quantum Physics Division currently includes 12 full-time permanent positions, of which 10 are for technical professionals. There are also four nonpermanent and supplemental personnel, such as postdoctoral fellows and part-time workers. Among the University of Colorado staff, there are 14 technical professionals. Subpanel members met with groups of graduate students, research associates (mostly postdoctoral fellows), and technical and administrative staff. All spoke freely. High morale and the belief that JILA is a very good place to work were apparent in all three groups. The students and postdoctoral researchers have great respect and appreciation for the technical support, especially the electronic and machine shops, and the staff take pride in supporting world-class

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 research and in helping students as well as Fellows. Shop staff will work unbilled overtime to complete jobs, and they feel free to initiate design suggestions. Students experience a sense of camaraderie and cooperation. Students feel that working “surprisingly” hard is the standard, and they believe that the Fellows work equally hard. Both the students and postdoctoral researchers are aware that they face a job market that has been tough in recent years, but they believe that JILA' s program to bring in speakers from industry and promote industrial connections serves them well. JILA's reputation is important in attracting postdoctoral workers but did not seem to have an effect on the graduate students. An issue raised by postdoctoral workers in astrophysics illustrates the divergence between the patterns in JILA and those that best serve training in astrophysics. The postdoctoral workers had three specific concerns: that the computing support is costly and not particularly helpful; that obtaining clearance for proposals for observation time takes 2 weeks at JILA whereas it takes less than 1 hour at the Center for Astrophysics and Space Astronomy, another University of Colorado astronomy organization; and that postdoctoral researchers are discouraged from teaching because the pay increment is low ($1,000) despite the fact that teaching experience is very important for astronomers. The realignment of the astrophysicists with the University of Colorado over the next several years may well address these issues. The subpanel sees the allocation and use of resources as key issues affecting the health of JILA and the determination of the directions in which the institute will develop. JILA is at a crucial transition point with decisions imminent in several important areas: the renewal of the staff, the creation of new programs, and the realignment of existing efforts. The planning associated with each of these changes is essential, and the resources required include, but are not limited to, funding. Any assessment of the adequacy of resources by the subpanel is intimately tied to future plans, and any planning must include a realistic consideration of the resources. The subpanel cannot make detailed observations about resource levels but does wish to outline some essential planning issues that are coupled to the decisions about resource requests and allocations. JILA stands today at the edge of an exciting new era. Its scientific achievements over the past few years are outstanding, and NIST management has recently indicated the prospects of good support for the institute. Nevertheless, over the next few years several JILA Fellows are likely to retire and the astrophysics subgroup may be separating from JILA. These two major changes would provide the institute with an unusual opportunity to shape the future course of its activities and, given its influence in the scientific community, to shape the future course of atomic and molecular physics. The decision by NIST some years ago to focus support on JILA activities outside of astrophysics plus the need for the University of Colorado astrophysics community to have its own central base appear to be the core forces driving the JILA Astrophysics Fellows to seek a separate identity. The good will and rationality that have characterized the process to this point are impressive. Planning for the future is critical and the subpanel hopes that it will proceed in the same spirit of good will and fellowship. An important first step is for the University of Colorado and NIST to reach a firm agreement about the number of JILA Fellows to be associated with the institute in the postastrophysics era. Numbers suggested during the subpanel's visit were 11 Fellows supported from University of Colorado funds and 11 from NIST funds. These numbers seem appropriate, and the subpanel expects that agreements about this issue will be solidified. Although it is logical that all of the Fellows will be in areas other than astrophysics, appointments are among the most precious of resources in a university. Thus, being certain that the new appointments will actually

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 be administratively within the new JILA and that the astrophysicists are comfortable with this arrangement is essential. A number of resource issues remain to be resolved. JILA management indicated that these issues pose no serious problems, and the subpanel is hopeful that at the next assessment it will hear about formal resolutions of these issues. For example, no space currently exists in which to house the entire astrophysics community at the University of Colorado. Therefore, the present Astrophysics Fellows are likely to remain within the JILA building complex for perhaps as many as 10 years. Several questions arise in this situation. Will there be sufficient space in the complex for new Fellows and how will support for the building complex be divided during this period? How will resources such as computer facilities, electronics, and machine shops be supported and managed during the transition period? Among the few complaints heard by the subpanel during its visit was some criticism by postdoctoral fellows in astrophysics regarding computer facilities. How much weight should be given to such concerns given the possibility of separation? Is there sufficient grant and contract support to maintain the high quality of the shops if the astrophysicists are not part of JILA? Decisions regarding new appointments are among the most important and difficult to be made in shaping the future activities of the institute. The subpanel was not clear about whether the astrophysics subgroup will still be involved in appointment decisions about new Fellows during the upcoming transitional period. Assuming the astrophysicists remain as JILA Fellows during most of the transition, their influence in determining the new directions of JILA might be considerable. Yet such a course seems illogical in light of their eventual separation from the institute. It would be more appropriate for the core remaining JILA Fellows to be charged with the responsibility and the opportunity to determine the direction of the institute. Finally, given the large number of potential new appointments of JILA Fellows, occasioned by retirement and new NIST and university commitments potential, it is critical to have a carefully developed plan for hiring. The subpanel estimates that in 5 years as many as one-half of the JILA Fellows could be new additions, depending on the rate of retirements and the commitment of both the university and NIST to new appointments. If the new appointments are delayed too long, the present positive atmosphere that favors them is likely to disappear. If the appointments are rushed, considerable strain will be placed on JILA's resources. For example, the subpanel sees the precision measurement and metrology effort as essential to JILA 's work and vitally connected to the NIST mission. However, identifying and making the appropriate additions to sustain that area may be a long and difficult process. Without a clearly articulated hiring plan, which surely will require significant discussions among the Fellows regarding future scientific directions, pressures to act quickly can lead to weak appointments and pressures to delay can allow crucial opportunities to pass. Either negative result would be tragic for an institute that has reached such a high level of success. In summary of the above discussion, the decision to separate the astrophysics work from the remainder of the activities at JILA is supported by the subpanel. This process will be long and complicated, and according to the subpanel, there are five issues that are critical for JILA to consider as a transition plan is formulated: a clear commitment regarding the number of JILA Fellows from the University of Colorado and from NIST in the postastrophysics era; a clear plan and time line for hiring, including who will make the hiring decisions; a clear plan and time line for space utilization and availability and a clear plan and time line for eventual moves; a financial impact statement regarding the changes that will occur when the astrophysics subgroup leaves and

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An Assessment of the NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY MEASUREMENT AND STANDARDS LABORATORIES Fiscal Year 1998 how the departure will affect the JILA operations; and a realistic estimate of retirements and plans for replacements. Major Observations of the Subpanel Major observations of the subpanel are presented below. JILA is at a crucial moment of change. The confluence of retirements, new research directions, and the decision that the astrophysics component will leave JILA brings the institute to a transition point. Management of this transition will require careful planning, obtaining the proper support from NIST and the University of Colorado, and vigilant implementation of the plan. Precision measurement and metrology are at the heart of JILA and its success. Renewing the institute in a way that allows it to maintain its preeminence in these areas is essential. The subpanel is convinced that efforts in these fields have enlivened the science at JILA and allowed the institute to obtain the respect and support that it enjoys in the scientific community. JILA has added excellent junior (Fellow-track) staff in the last 2 years. In the next few years, further additions of young staff who complement existing expertise and can carry JILA in newly defined directions are crucial. Now is the time to define the JILA of the future through careful discussion and planning. The institute has already taken an important step by deciding on a future in which the astrophysicists are no longer associated with JILA. Now the institute is faced with the challenge of obtaining the support necessary to implement this transition. Successful change is possible only if NIST and the University of Colorado are willing to provide the proper institutional backing. From the NIST viewpoint, the proposal to reshape JILA without an astrophysics component by adding two NIST Fellows and two University Fellows is sound. Retiring Fellows must also be replaced for JILA to maintain an appropriate size. Management of these hiring activities will require considerable work by the Fellows and others.