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8 . Education, Organization, and Decision Making in Elementary-Particle Physics HISTORICAL BACKGROUND Before 1960 Before 1940 research in nuclear physics and the construction of accelerators in the United States was carried out at universities and was funded from university general funds, in some cases supplemented by gifts or grants from corporations or individuals. Outside the uni- versities, few industrial and federal research laboratories constructed particle accelerators and carried out research in these areas. Perhaps the most notable research laboratory in the United States was at Berkeley' where E. O. Lawrence had developed the cyclotron and built a sequence of ever larger, more ambitious accelerators. With World War II and the knowledge of the German discovery of uranium fission, the U.S. nuclear-physics community began several major research and development (R&D) programs funded by the federal government. It is fair to say that big science was born at laboratories such as Los Alamos and Oak Ridge, as well as at large nonnuclear facilities such as the MIT Radiation Laboratory. Projects were accomplished not by one or two senior collaborators assisted by graduate students and skilled technicians, rather a larger group of senior and junior physicists together with professional engineers de- veloped and used large research facilities. I72

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EDUCATION. ORGANIZATION, AND DEClSlON MAKING 173 After the war, first the Office of Naval Research, then the Atomic Energy Commission. and later the National Science Foundation con- tinued the wartime pattern of federal funding of nuclear science. now again focused at universities. With the discovery of pions in cosmic rays in the late 1940s and the inventions of the betatron, synchrotron, and synchrocyclotron accelerators. a dozen or so major universities built accelerators of over 100-MeV energy to study high-energy nuclear physics. The physicists who implemented these projects applied their experience from the wartime laboratories, and consequently these machines were large, sophisticated engineering undertakings relative to the tabletop experimental equipment of prewar research. The Berkeley Radiation Laboratory built three large accelerators that became productive research instruments in the late 1940s. A group of East Coast universities meanwhile realized a need to develop a large, cooperative facility, and they joined together to form Associated Universities, incorporated (AU11. AUI acquired a former army camp on Long island and developed it into Brookhaven National Labora- tory. With funding from the Atomic Energy Commission but operated by AU1, the Laboratory built a 3-GeV proton synchrotron, the Cosmotron, completed in 1953. At Berkeley the 6-GeV Bevatron was completed in 1954, and large liquid hydrogen bubble chambers were developed there, extending the modes operandi of big science from the accelerators to the detectors used with them. During the 1950s, as the complexities of particle interactions and the rich spectra of meson and nucleon states began to unfold, high-energy or elementary-particle physics diverged from nuclear physics and became a distinct field. Although the boundary between these fields remains diffuse, it is appropriate to consider elementary-particle phys- ics as the study of the fundamental constituents of matter and the in- teractions between them. Nuclear physics, on the other hand, focuses more particularly on the many-body aspects of nuclear forces and nucleon systems. After 1960 in the United States During the 1960s, as the press to higher energies required larger accelerators and correspondingly larger detectors and experimental facilities, fewer laboratories became the dominant sites for high-energy research, and the 100- to 400-MeV synchrotrons and cyclotrons on university campuses were phased out. In the 1960s there were about eight accelerators with beam energies greater than I GeV in the United States. The largest accelerators at Berkeley, Argonne, Brookhaven,

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174 ELEMENTARI:PARTICLE PHYSICS Cornell, and Stanford were operated by laboratory staff and were used in part by physicists on those staffs. University physicists and their graduate students were major users of these large accelerators and began spending periods ranging from weeks to over a year in residence at the accelerator centers. Universities evolved research groups of one or more faculty mem- bers together with their graduate students, technicians, and post- doctoral research associates to undertake experiments at the national laboratories. Over the past decades these groups have increasingly worked in collaboration with groups from other universities and from the host laboratory. The funds to support the accelerator laboratories and the university user groups came from the Atomic Energy Commission (AEC), the National Science Foundation (NSF), and the Office of Naval Research (ONR). The support provided by the AEC has continued through its reorganization into the Energy Research and Development Agency (ERDA) and then into the Department of Energy (DOE). The ONR phased out its support in about 1970. The funding for the university user groups primarily pays for the fabrication of equipment, for travel, and for graduate student stipends. This support has also included salary for faculty members during the summer months, as well as occasionally during the academic year when intensive work on an experiment makes a leave of absence from teaching necessary. This university funding came in the form of research grants (NSF) and contracts (DOE) to the universities, growing in size to over a million dollars per year for some of the large university groups. The funding for the accelerator laboratories is used for the operation of the accelerators and experimental facilities, for the construction of new equipment and new accelerators, for partial support of the university groups that use the accelerators, and for support for the in-house physics groups that are part of the accelerator laboratory staff. The laboratories also engage in advanced R&D on accelerators and detectors. In 1965, an advisory group to the AEC recommended the formation of a new national laboratory to build a multi-hundred-GeV proton synchrotron as a national facility and to be operated by a nationally constituted university consortium. Thus in 1966 the Universities Re- search Association (URA) and the National Accelerator Laboratory [now the Fermi National Accelerator Laboratory (FNAL), or Fermilab] were formed, and an Illinois site was selected for that facility, now the site of the Tevatron.

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EDUCA TION. OR GANIZA TION, AND DECISION MA~'ING 175 During the 1970s there were six high-energy accelerator laboratories in the United States serving the eJementary-particle physics commu- nity: Brookhaven National Laboratory operated by AUI, Fermi Na- tional Accelerator Laboratory operated by URA. Lawrence Berkeley Laboratory operated by the University of California. Argonne National Laboratory operated by the University of Chicago, the Laboratory of Nuclear Studies operated by Cornell University, and the Stanford Linear Accelerator Center (SLAC) operated by Stanford University. At present there are four high-energyaccelerator laboratories: Brook- haven, Fermilab, Cornell, and SLAC. It may be noted that AU1 also operates the National Radio Astronomy Observatory at Greenbank, West Virginia, and the Very Large Array radio telescope at Socorro, New Mexico. The astronomers have emulated the particle physicists and have formed the Associated Universities for Research in Astron- omy (AURA), which now operates several astronomical observatories as well as the Space Telescope Science institute at The Johns Hopkins University. After 1950 Abroad The history of accelerator laboratories in Western Europe is similar to that in the United States. In the 1950s and 1960s there were about a half dozen high-energy accelerator laboratories in Europe, located in Great Britain, France, Italy, West Germany, and Switzerland. At present there are two, CERN in Switzerland and DESY in West Germany. In the middle 1950s European particle physicists joined together to form the European Center for Nuclear Research (CERN) in Geneva, Switzerland. CERN borrowed heavily from the organizational struc- ture of Brookhaven and AUI, and senior American physicists were consulted in developing the organizational structure of this pan- European laboratory and its administration. It was already clear at that time that this field of physics was among the most challenging and exciting of any area of science and that any nation or group of nations wishing to establish scientific leadership must excel in elementary- particle physics. CERN epitomized both that focus of intellectual excitement and a spirit of pan-European cooperation that has proven successful and productive. In Germany. the Deutsches Elektronen Synchrotron Laboratory (DESY) was established in Hamburg as a focus for particle-physics research. The series of electron accelerators and storage rings con-

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1 76 E' EMEN TAR Y-PAR TI CLE PH YSI CS structed there has made major contributions to particle physics over the past two decades. and continues to do so. The Soviet Union. with some international collaboration, has been active in elementary-particle physics. The Soviets have made major contributions in theory and in research on accelerator physics and technology. Several large accelerators have been built, sometimes at the highest particle energy. They have been less successful in acceler- ator operation and in exploiting their machines for high-energy physics experiments. During the last decade. the Japanese. always major contributors to theoretical particle physics. has been developing a major accelerator laboratory called KKK. They have a 19-GeV proton accelerator and are now building an electron-positron collider that will reach about 70 GeV. At present China is actively entering elementary-particle physics by building an electron-positron collider, called the Beijing Electron Positron Collider (BEPC). In Western Europe and Japan the organization and funding pattern are similar to those in the United States. The accelerators are located at a few laboratory sites; they are used by physicists from both the universities and the laboratories and the funding is from government sources. PACE AND PLANNING IN ACCELERATOR CONSTRUCTION AND USE Most experiments in elementary-particle physics use particle accel- erators or colliders; thus these machines lie at the heart of experimental work in this field. The size, complexity, and cost of these machines sets much of the pace and style of research work in this field. The design, construction, and operation of accelerators demands a level of planning and organization that exceeds that required in most other areas of science. It is therefore useful to look at what one might call the life cycle of accelerators. Conception The life of an accelerator begins when a group of physicists develops the general conception for a new accelerator. This may be based on a new invention in accelerator technology; for example. the Brookhaven AGS and the CERN PS proton accelerators were based on the invention of alternating-gradient focusing of beams in accelerators. The

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ED UCA TI ON, ORGA NIZA TI ON. A ND DECI SI ON MA KI NO 1 77 concept for a new accelerator may also arise because there is a need to go to hitcher energies or to more intense beams. and there is the real- ization that existing accelerator technology can be adapted to these new goals. This was the case with the 400-GeV proton accelerator at Fermilab and with the SPS proton accelerator at CERN. Proposal The passage from the initial conception of the accelerator to the beginning of its construction requires that a technical design be completely worked out and that the cost of constructing and operating the new accelerator be carefully estimated. This work results in a documented proposal that is submitted to the appropriate government agencies. Thirty years ago this was a relatively simple process; the proposal for the Brookhaven AGS was a six-page letter. In recent years, however, working out the design of a new accelerator has required years of effort and has involved scores of physicists and engineers in the process. The proposal itself is now typically hundreds of pages in length and is backed up by supplemental material in the form of reports from workshops and study groups. Decision The proposal is then subjected to a long review process by the government agency involved. Groups inside and outside the agency review the physics justification. the technical soundness, and the cost, and they compare these with competing proposals. For large acceler- ators this process may include analyses by the legislative as well as executive branch. Construction The start of construction of a new accelerator is not always a clear date. initiation of construction may include acquisition of the land site for the accelerator, the first ordering of materials and supplies, or the setting up of shops and laboratories to begin construction of compo- nents. The completion of construction is usually formally marked by the time when the first particle beams are produced. This time is often followed by a period of a year or more during which the accelerator is brought into more efficient operation. the energy of the primary beam is increased, and the intensities of the primary and secondary beams are also increased.

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178 ELEMENTARY-PARTICLE PHYSICS Use of Accelerators for Physics e Outside of the field of elementary-particle physics there is sometimes the notion that an accelerator is built to carry out a certain set of specific experiments and that after those experiments are completed the accelerator is closed down. In fact the situation is very different. Of course the early experiments do carry out the initial goals for which the accelerator was built. But then new physics ideas and new ideas in particle detection lead to experiments on the accelerator for which it may not have been designed. Often the major discoveries made with an accelerator are not those for which it was originally intended. As the accelerator matures. it takes on an even more varied life. Often it is extended once again in energy or in intensity. Sometimes, even more surprisingly, it can be converted into another type of facility. Two examples are the use of the Cornell 10-GeV electron synchrotron as an injector for the CESR electron-positron colliding-beam storage ring and the partial conversion of the CERN SPS proton synchrotron into an extraordinarily successful proton-antiproton colliding-beam storage ring. Other examples are the use of the SLAC linear accelerator as an injector for the SPER and PEP electron-positron storage rings; the use of the DESY 6-GeV electron synchrotron as an injector for the DORIS and PETRA electron-positron storage rings; and the recent conversion of the 400-GeV Fermilab accelerator into an injector for the 1000-GeV superconducting proton ring at Fermilab. The Death of an Accelerator Accelerators are shut down when other machines are more effective in carrying out the physics that can be done at that accelerator. or when there are insufficient funds to continue the operation. Appendix A lists most of the major high-energy accelerators built in the United States and in Western Europe during the last 30 years. Perhaps surprisingly, many of these accelerators are still in use. Two examples where lack of funding caused the shut down are the ZGS machine at Argonne and the ISR proton-proton storage ring at CERN. Of the accelerators now in operation, some have had an extraordinary long life. For example, the Bevatron at Lawrence Berkeley Laboratory has been in use for almost 30 years; it is now being used as a heavy-ion accelerator. Another way to measure the usefulness of an accelerator is to see when its major physics discoveries were made. Sometimes, as one would expects major discoveries occur early in the period of use of an accelerator: for example, the psi (~) particle and the tau (T) lepton were discovered ~ 4

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EDUCATION, ORGANIZATION' AND DECISION MAKING 179 and 3 years, respectively, after the completion of the SPEAR storage ring. Another example is the discovery of the Y particle at Fermilab 4 years after the 400-GeV accelerator began operation. On the other hand, the J particle was discovered at the Brookhaven AGS 14 years after the AGS began operation! Summary Thus the life cycle of accelerators spans decades. and the decade is the natural unit to use in thinking about the planning and construction of accelerators. It is also the natural unit for thinking about the pace of experimental research in particle physics and the pace at which new accelerator technologies can be developed. This final point deserves some emphasis. The development of new accelerator technology begins with new ideas such as phase stability' or alternating gradient focusing, or the collision of two beams in a storage ring. But it is a long and difficult path from the new idea to the actual accelerator. Usually the full exploitation of the new idea requires several successive steps in the building of accelerators that go to higher and higher energies or intensities. For example, the concept of a linear accelerator goes back to the late 1920s, but the full use of that idea in the SLAC linac in the 1960s required the building of several smaller linear accelerators in the 1940s and 1950s. Hence, the natural unit of time we use is the decade. This means that our planning must extend over several decades. THE NATURE OF ELEMENTARY-PARTICLE PHYSICS EXPERIMENTATION As noted earlier, many experiments in elementary-particle physics are now carried out by large groups of physicists using powerful detectors of large size and complexity. There are exceptions; these include some small-group experiments at high-energy accelerators' at nuclear-physics accelerators, and at reactors and those using cosmic rays. But large-group experiments now dominate, and will continue to dominate, this field. In this section we examine the nature and style of such research. Large groups including physicists, engineers, and technicians have become necessary because the research apparatus is large and com- plex. It takes many people to build the experimental apparatus, to maintain it, and to operate it on a 24-hour-a-day basis for months at a time extending over a year or more. If we look more closely at such groups. we see that the cooperative work is made up of a number of

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180 ELEMENTAR}:PARTICLE PHYSICS coordinated individual activities. The individual nature of the work is especially evident during the design and prototype stages of apparatus construction and also during the data study and analysis stage of the experiment. . During the early stages of the experiment, it is often just one or several physicists who design and build the prototype for a major part of the apparatus' such as a drift chamber or a calorimeter. These physicists are then working in much the same way as physicists working in other fields of research: trying out new ideas in the laboratory. testing new construction techniques, and building proto- types. And this work may include all the traditional skills of the physicist in such areas as mechanical design, electronic design and testing, and fabrication of initial components in the research shop. In such work there is a premium on innovation and improvement of techniques, on simplicity and economy, and on getting the job done right. The other stage when individual research effort is most important in large-group experiments is at the time of data study and analysis. Almost always just a few physicists sometimes just one physicist. will concentrate on a particular aspect of physics in the data. For example, in a typical electron-positron collider experiment, different people will be studying different topics such as charm meson or bottom meson physics, or electroweak interference, or searches for new particles. These individuals or small groups tend to carve out a piece of the physics and pursue it on their own. The success or failure of that piece of research depends on the skill and luck of those individuals, just as it does in other areas of science. The publications that report the results from a large-group experi- ment are usually signed by the entire group, in recognition of the cooperative effort needed to build and operate the apparatus. But the elementary-particle physics community is relatively small. and within the community it is usually well known who made the leading contri- bution to the particular piece of physics. Often this is recognized by putting the names of those who did that particular piece of work at the beginning of the list of authors. A large-group experiment, particularly at a collider, is best looked at as being equivalent to the sum of many different individual experiments of the kind that are carried out at the older fixed-target accelerators. The experimenters have banded together to build one large and complex detector. The price one pays is that there must be a good deal of cooperative work and that it is difficult to rework or rebuild the apparatus quickly. The gain is that the apparatus is very powerful, more powerful than the sum of its parts. Frequently. its power allows

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EDUCATION ORGANIZATION, AND DECISION MAKING 18 20 \~\ 1 500 1 000 `,, 500 . _ In - , , , , I r - - o - , , 1 1 1 1 970 1 975 1 980 .. FIGURE 8.1 Top: Percentage of physics doctorates granted in the United States that were in elementary-particle physics. either experimental or theoretical. Bottom: Number of physics doctorates granted in the United States. one to do new physics that could not be done by a set of separate and simpler experiments. indeed, particularly with respect to new particle searches, the large detector permits physics to be done for which one would not have dared to build a special apparatus. Thus it permits speculative physics to be carried out, as well as physics of known phenomena. GRADUATE EDUCATION About 1000 doctorates in physics are granted in the United States each year, as shown in Figure 8.1. The physics subfield granting the largest number is solid-state physics; elementary-particle physics ranks second. In 1982, about 12 percent of all physics doctorates granted in the United States were in particle physics, and the dissertations for these degrees were about equally divided between experimental and theoretical physics. The attractions of elementary-particle physics to the physics gradu-

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182 ELEMEA'TAR Y-PARTIC' E PH YSICS ate student are manifold. Elementary-particle physicists work at the boundary of our knowledge of the nature of matter. Students working on experiments build and use equipment that involves a great range of physical principles and instruments: ionization phenomena in tracking chambers, ultrafast solid-state devices in electronics. high-speed com- puters, cryogenics systems, and superconducting magnets, for exam- ple. Students of theory learn to use new and general theoretical principles such as gauge theories. renormalization group methods, and symmetry breaking. Thus they develop ~ general problem-solving ability of high order. Elementary-particle physics is an active field, and roughly half of those who are educated in it stay in it. Those who leave the field find excellent uses for their training in other areas. The graduate education of students in experimental particle physics has been frustrating at times, in view of uncertain experiment sched- uling and the occasional breakdown of an accelerator conditions well beyond the control of the student or his research group. However. the students in research groups gain unusual experience and exposure in other areas. A typical graduate student will complete course work and work on apparatus development at a home university and may then work at a national laboratory for a year or morel setting up. debugging and collecting data with this equipment. The student then returns to the home university or perhaps continues at the laboratory to carry out the data analysis. Thus the student carries out an individual piece of physics through individual data analysis. While at the laboratory, students are exposed to an international stream of visitors, seminar speakers. and informal contacts. They have the opportunity to interact with engineers and technicians as well as faculty and students from other institutions and with practicing phys- icists. The home university and thesis advisor meanwhile continue to provide the continuity and pedagogical foundation around which this broadening experience is molded, exposing the student to the broader range of physics and the other sciences. INTERACTION BETWEEN THE PARTICLE-PHYSICS COMMUNITY AND THE FEDERAL GOVERNMENT Universities The DOE and the NSF support the university users programs. Peer review of research proposals and the alternative of two different agencies have provided a fair and responsive federal structure for the support of university research in this area. New proposals are often

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CD~CATlON. ORGA NIZA T/ON. A ED DECISION MA~'/NG I 83 submitted to both agencies, and communications between the two sets of Washington physicist-administrators have been good while still maintaining the unique character and perspective of each agency. An experimental research group must not only attract support from the federal agencies but must also succeed in persuading the program committee advising the accelerator laboratory to allocate accelerator time. Program committees always have members from all parts of the U.S. particle-physics community and often from abroad. This degree of scrutiny of proposals leads to a close filtering of ideas and to a generally high success rate of groups and experiments. The potential liability of this system is that it might tend to choke off unconventional ideas or high-risk explorations. The community is cognizant of this pitfall and has been successful in providing opportunities for explor- atory ventures. The Report of the Technical Assessment Committee on University Programs (U.S. Department of Energy, DOE/ER-0182, 1983) to the Division of High Energy Physicsq DOE. discusses those points in much more detail. Accelerator Laboratories The DOE supports the Brookhaven, Fermilab, and SLAC accelera- tor laboratories, while the NSF supports the Cornell accelerator laboratory. The work of these laboratories is guided and reviewed in a number of ways by the particle-physics community and by the funding agencies. Each laboratory has a visiting committee that reports to the university body that operates the laboratory. The funding agencies make periodic reviews of the physics research and technology devel- opment work of the laboratories. Finally, the High Energy Physics Advi- sory Panel (HEPAP), discussed below, provides a general overview of the accelerator laboratories. HEPAP's role is particularly important when new accelerator construction is proposed. At Brookhaven, Fermilab, and SLAC the external university users have formed user organizations. These work with the laboratory administrations on the problems of the visiting physicists and graduate students, as well as on other issues relevant to the research environ- ment and capability of the laboratory. Decision Making and Advice Since the end of World War 11 senior scientists have advised the government in several different ways. The AEC had a General Advis- ory Committee and, later. under President Eisenhower, a President's

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184 El EMENTARY-PARTICLE PHYSICS . Science Advisory Committee was established. The NSF includes in its advisory structure the National Science Board with members named by the President. In the 1950s a series of decisions related to major new facilities was necessary. An initiative by a group of Midwestern universities to develop a laboratory along the lines of Brookhaven, the desire of the Argonne Laboratory to build a large accelerator, and a Stanford plan for a large electron linear accelerator led the government to seek advice from advisory panels. In 1967 the AEC formed a standing committee to advise it on the issues it confronts in making decisions in particle physics. This High Energy Physics Advisory Panel (HEPAP) continues to the present. Its 15 members, named for 3-year terms. represent a broad cross section of university and laboratory stab physicists both theoretical and experimental. The members are named by the Secretary of Energy, with the advice of the DOE director of research for particle physics. HEPAP meets about five times a year. Its agenda is set by the DOE and usually focuses on immediate questions faced by the DOE in particle physics, such as budget issues, program reviews. and international collaboration. HEPAP also appoints subpanels, shown in Table 8. 1, to study special questions or broad areas of planning. Its most important decisions relate to the overall direction of the field through its endorse- ment or rejection of proposals for construction of new facilities. The NSF Program Director for Elementary Particle Physics also regularly attends HEPAP meetings, and the NSF program is included within the purview of this panel. The successful pattern of HEPAP has now been adopted by the nuclear physicists with the formation of the Nuclear Science Advisory Committee (NSAC). The program committees and user organizations at the major accel- erator laboratories have already been mentioned. In addition, the membership of the Division of Particles and Fields (DPF) of the American Physical Society (APS) includes most of the elementary- particle physicists in the United States. Although the DPF has been primarily concerned with planning programs for APS meetings in the past, it now shows promise of becoming more active in policy and planning issues. During the summer of 1982 the DPF organized a 3-week workshop on current questions of particle accelerators, detec- tors, and physics. The initial planning for the very-high-energy proton- proton collider, the Superconducting Super Collider (SSC), can be traced directly to that meeting. A DPF 3-week workshop in the sum- mer of 1984 was concerned with more detailed planning for the collider. The European particle-physics community has analogous institu-

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EDUCATION, ORGANIZATION. AND DECISION MAKING 185 TABLE 8.1 Listing of Subpanels of HEPAP 1970 Subpanel on Computer Usage in High Energy Physics 1971 Subpanel on Advanced Accelerator Technology 197~ Subpanel on Future Patterns of High Energy Research 1972 1974 1975 1975 1975 1976 1977 1918 1978 1979 1980 1981 1983 1983 Subpanel on Research and Program Balance Subpanel on New Facilities Subpanel on Communicating the Meaning and Accomplishments of High Energy Physics Subpanel on Requirements of a Vigorous National Program in High Energy Physics Subpanel on Computing Needs Subpanel on New Facilities Subpanel on Study of impact of Full Cost Recovery on High Energy Physics Community Subpanel on High Energy Physics Manpower Subpanel on Accelerator R&D Subpanel on Review and Planning Subpanel on Long Range Planning for U.S. High Energy Physics Program Subpanel on New Facilities Subpanel on Advanced Accelerator R&D lions. CERN is governed by a council, consisting of both scientific and political representatives from the CERN member nations. A Scientific Policy Committee advises the CERN Council. In addition, there is a standing European Committee on Future Accelerators (ECFA) that considers long-range planning issues for Europe. The European deci- sion-making process has been generally successful in recent years; the decisions leading to the ISR, the SPS, the proton-antiproton collider, and now LEP have been difficult but are generally agreed to have been timely and correct. INTERNATIONAL COOPERATION AND COMPETITION The international nature of elementary-particle physics goes back to the turn of the century. In that period there was no distinction between atomic physics, nuclear physics, and elementary-particle physics, and the great discoveries and advances in those fields came from the na- tions of Europe. By the 1920s and 1930s, contributions had also begun to come from America and from Asia. The Second World War stopped almost all basic research in Europe and Asia, and in the United States the research establishment was mobilized to develop radar and nuclear and other weapons. After the war, the United States continued to support substantial research in nuclear physics, as well as in elementary-particle physics as

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186 ELEMENTARY-PARTICLE PHYSICS it evolved to become a distinct field. But the destruction caused by the war in continental Europe and in Asia left those regions unable rapidly to resume their traditions in nuclear-physics research. First they had to rebuild their economies and their academic institutions. Thus, for about two decades following the end of the war, substantial progress in particle physics came primarily from the United States and Great Britain. With its greater resources and stronger economy, and aided significantly by its European immigrants, the United States assumed the leadership role in the world in elementary-particle physics re- search. By 1960, Europe. Japan, and the Soviet Union had strengthened their economies and had begun to carry out active research in elementary-particle physics. At the same time international coopera- tion in elementary-particle physics was developing. This cooperation has assumed many forms. The authors and readers of particle-physics journals come from literally dozens of different nations. There have been international meetings and conferences in particle physics every year since 1956. international visits to university and laboratory parti- cle-physics facilities are extensive. Often a physicist will work abroad for several years with a research group in the host country. There is another form of international cooperation that takes advan- tage of the moderate to large size of many particle-physics experi- ments. A group of physicists from one nation can build all or part of an experimental apparatus and take it to another country to use with that country~s accelerator. This helps to share the cost of an experiment, makes use of special equipment available in one country, and increases the power of an experiment. American groups have mounted experi- ments at the CERN and DESY accelerators in Europe. Currently one of the large detectors being built for the LEP electron-positron collider at CERN is directed by an American. Thus far. fewer Western Europeans have come as entire groups to use U.S. accelerators, although Japanese groups have been contributing substantially to experiments at accelerators in the United States and in West Germany. This form of cooperation in the building and operating of detectors is particularly important for the health of the field. Progress in elemen- tary-particle physics depends in the end on successful experiments, and those experiments in turn depend on the quality of the apparatus used. international cooperation helps to improve the quality of the apparatus, while sharing costs. Some international cooperation pro- ceeds informally on a scientist-to-scientist or laboratory-to-laboratory basis, while other efforts are covered by formal intergovernmental agreements. Of course, the outstanding example in our field of an inter-

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EDUCA TIO~'. ORCANIZA HON AND DECISION MAA'ING 187 national joint venture is the CERN laboratory in Switzerland. This highly successful laboratory, founded in 1954. is supported by almost all of the nations of Western Europe. In the future, entire collision regions at colliders might be allocated to foreign groups with some appropriate arrangement for funding and staffing from foreign sources. Given the recent disparity between Western Europe and the United States in the support of new facilities, there is understandably more use by American physicists of European facilities than vice versa. In all of science. there is some competition along with cooperation. Such competition is necessary for the vigor of science. Competition maintains high standards; it generates diversity of methods and pro- vides cross-checks of experimental findings; and it spurs the scientist to be more inventive. to think harder. and to work harder. lnternation- ally both cooperation and competition exist; the issue is to maintain an appropriate balance between the two. With respect to elementary-particle physics, the United States had little concern with the right balance between international cooperation and international competition until the last decade. Until the middle 1970s. Western Europe and Japan were still building up their particle- physics research and the United States led the world of elementary- particle physics. Howeverq this is no longer the case. and we must now consider the balance between cooperation and competition. The elementary-particle physics community in the United States has developed some guidelines that are intended to maintain this balance: (a) The continued vigor of elementary-particle physics in the United States requires that there be some forefront accelerator facilities in the United States. (b) The most productive form of cooperation with respect to accel- erator facilities is to develop and build complementary facilities that allow particle physics to be studied from different experimental direc- tions. (c) The present forms of international cooperation should be contin- ued and supported. . These guidelines are being followed at present. The two accelerator facilities now under construction in the United States are the Tevatron proton-antiproton collider at Fermilab, which will have the highest energy in the world; and the Stanford Linear Collider' which will provide high-energy electron-positron collisions using a new accelera- tor technology. Western Europe has under construction a hi'~her- energy electron-positron circular collider. LEP. using conventional

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188 ELEMENTARY-PARUCl E PHYSICS e accelerator technology, and is building an electron-proton collider called HERA. Thus, at the new collider facilities completed or to be completed during this decade (Appendix B)' there will be ten experi- ments (beam-intersection) areas in Europe (two at the CERN pp collider, four at LEP, and four at HERA) but only three in the United States (two at the Tevatron and one at SLAC). Therefore, there is now a significant migration of American experimental physicists to exploit the more available European experimental opportunities. There have been repeated discussions of a truly international accel- erator, financed and constructed by a global collaboration. But inter- national cooperation in science, while improving, has not yet reached the point where this appears practical. Questions of the design of the accelerator, of site selection, of funding, and of the allocation of experimental time all appear too unwieldy to be managed by any existing international mechanism. But perhaps most important, the economics of the construction and operation of an international ac- celerator are not clear. One of the main reasons for international cooperation would be to share the costs, thus reducing the cost borne by each nation. However, the construction and operating cost effi- ciencies would certainly be decreased in an international effort. For example, the award of construction contracts could not be based solely on lowest bid or best performance, since some consideration would have to be given to spreading the contracts out over the nations contributing to the construction. As another example, design and specifications would become more complicated because of different national technical standards and styles, thus increasing costs and construction time. Thus decreased efficiency would cancel to some extent the hoped-for savings in shared costs. This is a particularly important consideration if the foreign contributions are not large. There are, however, good reasons for increasing international col- laboration beyond the current pattern. Even limited financial contribu- tions of other nations to a new accelerator venture deepens the commit- ment of all parties. international planning carried out on a nonbinding basis could avoid possible technical mistakes and could help to forge tighter bonds within the international community. The roles of the International Committee on Future Accelerators (1CFA) and of the Summit Working Group on High Energy Physics have recently been strengthened in this respect. We welcome these valuable additions. Thus the time is not yet ripe for a truly global collaboration. Through the next generation of accelerators' including the proposed very-high- energy proton-proton collider. the SSC, it seems sensible to retain the,

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EDUCA TION, ORGANIZA T/ON, AND DECISION MAR'ING 189 primary funding. the governance, and the management of the SSC in the United States. international help and cooperation should be sought in providing some of the experimental facilities and possibly some of the construction cost. The management should ensure that the accel- erator is open to the entire international particle-physics community and that mechanisms for collaboration with non-U.S. physicists and research teams are developed and encouraged. But the U.S. elemen- tary-particle physics community, working with the federal govern- ment. must assume the primary responsibility for initiating and building this accelerator. FUTURE TRENDS AND ISSUES In the final section of this chapter we describe some of the future trends that we perceive in the organization and education associated with elementary-particle physics. We also discuss some issues that may arise and make some recommendations aimed at resolving those issues. Graduate Students' Role Particle physics has always been characterized by an infectious intellectual excitement, and this is currently being fueled by remark- able advances in our understanding of elementary particles. While this continues to attract good students into the field, the appeal of a Ph.D. thesis research program in experimental particle physics is tempered by the potential for a long and uncertain schedule and by the perception of an impersonal relationship as a member of a large team. As with every field of science, the future vitality of the field is critically dependent on the quality of young people who enter as graduate students and constitute the young Ph.D.s. The particle-physics com- munity must strive to maintain modalities that will make it possible for graduate students to play a significant, creative role in these large experiments and to complete a Ph.D. thesis in a reasonable time. Basically, as discussed above, graduate students must continue to have the opportunity to carve out specific pieces of physics for their own research. Scientific Manpower in Particle Physics The demographics of the field should be well understood. The quality and quantity of the graduate-student influx into particle physics, the

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190 ELEMENTARY-PARTICLE PHYSICS . dispersion of particle physicists into other areas, and the division between theory and experiment should be known and monitored. The particle-physics community has remained at nearly a constant size in spite of producing new Ph.D.s at a rate of several percent of its total per year. About half or more of the particle-physics Ph.D.s use their education to move into fields as diverse as astronomy, fusion research. computer science, and nuclear medicine. Because particle physics is entirely basic research with no direct applied aspects, no industrial laboratories maintain significant particle-physics programs, and the field exists entirely within the universities and the national laborato- ries. As university undergraduate enrollments shrink between now and the end of the century the universities will be able to justify fewer faculty positions, and as particle physics is a young field, relatively few faculty in this area will retire soon q as is apparent in Figure 8.2. It thus may be necessary to fund through federal grants and contracts increas- ing numbers of research faculty and research scientist appointments in particle physics at universities in order to maintain the youth and vitality of the university programs. There is some evidence of a trend in this direction; it should be understood, monitored, and supported. Competent young scientists should be able to perceive a clear career ladder in the universities as well as in the national laboratories. Advanced Accelerator and Detector Research It is clear from Chapter 5 that the particle-physics community has invested substantial effort and ingenuity in the invention and develop- ment of particle accelerator systems over the past 50 years. Corre- spondingly, the future progress of the field depends on the continuation of this trend. With the concentration of elementary-particle physics accelerators into only four laboratories in the United States, and with only two of these at universities, few graduate students are being educated in the physics of particle accelerators. In the programs of the large laboratories there is generally some provision for work in advanced accelerator research. But often, when budget reductions occur, this research may be sacrificed in favor of maintaining a strong experimental research program and the momentum of construction of authorized new facilities. A method should be developed to educate young physicists in accelerator theory and to support in a consistent manner long-range research in particle accelerators. This is essential not only for the long-range future of particle physics: accelerator physics is a significant

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ED{JCATION, ORGANIZATION. AND DECISION MAKING 191 Retirement Year ot Age 65 1 985 1 995 2005 20 1 5 2025 8O:?2 1 1 _ 60 ' 40 a) - o o ~ 20 Age Distribution _ of "Sen ior" Experi mental ists (a) 40 20 o Age Distribution of "Senior" Theorists For rL ~ (a) l ~ 1 - - 1 920 1930 1940 1 950 1960 Year of Birth FIGURE 8.~ Age distribution of senior experimentalists and theorists in elementary- particle physics. Senior means associate and full professors and laboratory equivalent. (Report of the Technical Assessment Committee on University Programs. 1983.)

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192 ELEMENTARY-PARTICLE PHYSICS . area where particle physics overlaps other fields, and the spinoEfrom accelerator physics to other fields has been particularly valuable. There is no reason that future accelerator research and development should not continue this trend. Similar remarks are appropriate with reference to detector develop- ments. Although advances in detector concepts and design are still dispersed among the universities as well as the laboratories, there is a trend here as well to reduce this effort and to concentrate it at a few national laboratories. It remains true that an advance in detector technique can be equivalent to an improvement in accelerator beam intensity or luminosity in the study of new phenomena. Encourage- ment and support of detector development, at the universities as well as at the large laboratories, should continue. Laboratory Management The particle-physics community has been comfortable with the management of the large laboratories by universities, either singly or in consortia. There is no motivation to change this arrangement. If ~ new laboratory is created around the SSC, it might best be managed similarly, most probably by a national consortium of universities. The management by universities or university consortia of the large accel- erators of today facilities costing in excess of a hundred million dollars has resulted in an enviable record in terms of meeting goals of performance, budget, and schedule. One might question whether the scale of the SSC is so far beyond our current experience that an industrial management group, familiar with the implementation of very large high-technology projects for the government, might be ~ better alternative. Yet there is no evidence that performance by industry in major space projects, reactor construction projects, or large highly technical military systems has been superior; if anything there is evidence in the opposite direction. Moreover, the particle-physics community Is in favor of university management, and a strong case would need to be made for an alternative. The basic research in particle physics, even on the Olympian scale of the SSC, will have scholarly academic goals, and the SSC must be managed to maintain this focus. University management furthermore buffers the laboratory from polit- ical and commercial motivations that might enter under other manage- ment structures. One change in past practice that could be considered for ~ new laboratory would be the limitation of a director's tenure to 5 (or so) years, as is the case at CERN. Although such a policy for the existing

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EDUCATION. ORGANIZATION. AND DECISION MAKING 193 laboratories might also be desirable, the responsibility for such a change must rest with the managements of the respective laboratories. A 5-year term would have the advantages.of maintaining leadership vitality and of encouraging productive scientists to accept a director- ship without the implication of a commitment for the duration of a professional career. Alternatively, a 3- or 4-year term' renewable once only, might be considered. Advisory Structure . HEPAP has been generally successful. This kind of peer input into the federal decision-making process is obviously elective. The frequent convening of ad hoc panels to consider long-range planning issues and other specific questions is evidence that commu- nity input beyond that of HEPAP is also important. There has been occasional discussion about establishing a standing long-range planning committee in the United States, analogous to ECFA in Europe, but there is no consensus on this question. It appears that the Division of Particles and Fields of the American Physical Society will become increasingly active through its organization of workshops and studies, and these will contribute significant community input to the decision- making process. It is in any event most desirable to continue to examine and improve the planning mechanisms for high-energy physics.