FUNDING OF PARTICLE PHYSICS

Elementary particle physics is the study of those particles that are considered not to have measurable spatial dimensions or further constituents. The designation of particles as "elementary" has changed in time as substructures of what were previously thought to be elementary particles were found. During the last century, particle physics evolved from atomic physics, to nuclear physics, to what is now called elementary particle physics. It was recognized that atoms were constituted of nuclei surrounded by electrons and then that nuclei were composed of neutrons and protons. Information was developed about the forces acting between neutrons and protons, and this led to some understanding of nuclear structure. Beta decay was discovered which converted neutrons into protons and vice versa with the emission of an electron and a neutrino. During the last quarter of the century, it was found that neutrons and protons are composed of quarks of six "flavors," and the electron was found to have two "brothers," the muon and the tau, constituting the lepton family. This evolution in knowledge was furthered by three branches of particle physics: theoretical physics, accelerator physics, and experimental physics. In turn, experimental physics uses accelerators, radioactive sources, or cosmic rays.

Before World War II, this work was supported by largely private sources—either industry or foundations. Some of the biggest accelerators operated in industrial laboratories such as the Westinghouse research laboratories that housed large electrostatic accelerators. Facilities at universities were generally sponsored by foundations. The Radiation Laboratory at Berkeley founded by Ernest O. Lawrence was unusually successful in obtaining private funding and supported the construction of families of cyclotrons, some of which were contributed to other laboratories.

During World War II, physicists demonstrated that if adequately supported, they could create and organize effective laboratories and produce spectacular results. Based on this wartime experience government became interested in supporting particle physics research on a large scale. Part of the support came from unobligated funds of the military agencies; the Office of Naval Research and also the Office of Scientific Research of the Air Force supported fundamental research at universities. Separately the Atomic Energy Commission, the follow-on agency to the wartime Manhattan District, supported fundamental research in addition to its applied missions. In fact some of the senior physicists, such as Enrico Fermi, returning from wartime to academic research were urged by the government to accept grants for the construction of particle accelerators.

This postwar expansion of government support of particle physics was partially accidental due to funds remaining in government coffers but was also a deliberate effort to encourage physicists to do in peacetime what they had so ably demonstrated in war—to organize large successful laboratory efforts. Thus World War II led to a shift from private to government support of elementary particle physics. With very few exceptions this shift proved irreversible, and elementary particle physics has become the ward of the federal government in the United States and of governments abroad. In the United States the Department of Energy as successor to the Atomic Energy Commission has remained the "custodian" of the particle physics program with the National Science Foundation supporting university based activities and one accelerator center.

Elementary particle physics attacks some of the most fundamental questions of inanimate nature— that is, the search for the fundamental building blocks of the universe and the forces between them. It thus attracts extremely capable people, and these tend to be intolerant of the limitations imposed by available tools. While practical applications of elementary particle research rarely result from the discoveries from that research, the invention and development of the tools that elementary physicists devise to further their work has extensive economic consequences. The electromagnetic cavity invented by W. W. Hansen, which is now an essential component of most microwave devices, was originally devised to provide high voltages for particle research with only moderate amounts of radio frequency power. Microwave linear accelerators that were developed for elementary particle physics have become a near-billion-dollar industry supplying radiation sources for cancer therapy. The large variety of radiation detectors developed for elementary particle physics have been of enormous value for monitoring devices for the reactor industry and in medical practice. Particle physics has led to the world's most intense X-ray sources—synchroton radiation—applied to many industrial uses.

A similar pattern prevails in the field of data handling and communications. The World Wide Web was initiated first at the European Laboratory for Elementary Particle Physics (CERN). The first communication link between the United States and China was established in connection with the need to transmit vast quantities of data in the collaborative effort between those two countries. Many of the algorithms for identifying very rare events among a large class of phenomena, for recognizing specific patterns, and for modeling complex sequential phenomena were developed in elementary particle physics but then widely applied.

While research in elementary particle physics has produced many dramatic economic consequences, private industry has been reluctant to support fundamental research. Practical results from elementary particle physics are delayed, and financial returns can rarely be recovered by the particular entity that supports the work.

Governmental agencies recognized that support of elementary particle physics is difficult to justify economically by its direct results, but the history cited above has amply demonstrated that such research has provided a dramatic return on the public investment. While it is extremely difficult to develop an "audit trail" between the funds invested in elementary particle physics and the returns to society, many economic analyses have been made to estimate the rate of return of investment in fundamental research. The results of such analyses vary widely; calculated rates of return range from 20 to 50 percent— very large figures, but difficult to pin down precisely.

However, by the beginning of the twenty-first century, government began frequently to forget these facts and would like to see a definite demonstration of a direct causal relationship between investment and returns. Should governmental funding be invested in directed research to answer specific questions of an applied nature rather than rely on "spinoff" from fundamental work? History should be persuasive: the most fundamental questions of nature attract highly capable people, and they in turn provide solutions that then result in practical applications.

FIGURE 1

As the energy of accelerators has grown by seven orders of magnitude during the last century, the cost per unit of energy has shrunk by about a factor of 10,000. Thus the construction cost of a single new machine continues to increase, and therefore worldwide the number of "accelerator centers" has shrunk. These laboratories are operated as facilities for a large community of "users," generally faculty and students at universities. By this method the educational role of particle physics through graduate education is maintained even when the actual collection of data is concentrated at a decreasing number of centers.

Notwithstanding the growth in energy at the particle physics frontier, the large community of particle physicists, the history of production of profound basic revelations, as well as the generation of practical technologies, U.S. funding for particle physics has shrunk by about 20 percent in real terms over the past twenty years as shown in Figure 1. That chart shows the funding history in constant 2001 dollars adjusted by the Consumer Price Index (CPI) + 2 percent per year. The latter correction is necessary since a large fraction of the cost of particle physics research is salaries which in technical fields have grown faster that the CPI.

Particle physics is an international enterprise. 2002's annual budgets for the field are distributed approximately as follows: Europe $1.0 Billion; U.S. $0.7 billion; Japan $0.3 billion; Other ~$0.1 billion. The budget of CERN is almost as large as the sum of the large centers of other countries combined.

The future economic needs of particle physics is difficult to predict because a number of factors are expected to affect the pattern of work within the field:

• Nonaccelerator physics, such as large cosmic ray and neutrino experiments, is becoming of increasing interest.
• There is an increasing overlap of subject matter in studies of particle physics and cosmology, that is, the study of the very small and the very large.
• New accelerator technologies are under intensive study.
• To continue the remarkable history of contributions to knowledge, future particle physics facilities operating at the frontier must demonstrate large increases in three respects: particle collision energy, rate of collision, and data analysis capability.

The general consensus remains that future accelerator centers at the frontier will be one-of-a-kind laboratories constructed and operated with international support. Today (2002) large detectors at regional facilities are internationally financed, constructed, and operated, and that practice may be extended to the accelerators and their infrastructure also. This does not imply that a single nation or region could not "afford" greatly increased support for basic science; the budgetary level of funding for fields such as particle physics is a matter of policy, not fiscal necessity.

See also:Benefits of Particle Physics to Society; International Nature of Particle Physics

Bibliography

American Institute of Physics. "FYI: the AIP Bulletin of Science Policy News." <http://www.aip.org/enews/fyi/>.

Wolfgang K. H. Panofsky