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OCR for page 172
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,
OCR for page 174
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
OCR for page 179
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
OCR for page 191
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.
Representative terms from entire chapter:
international cooperation
