estimate of the SSC construction costs which will be carefully reviewed by the Department. Relative to funding needs and the need for a supplemental request for SSC R&D in FY 1987, we believe that by focusing on the most critical SSC R&D requirements, the highest priority FY 1987 needs for SSC R&D can be accommodated within the high energy technology budget where it was funded in FY 1985 and FY 1986.

Question: What plans are there for further building at CERN, beyond the use of superconducting magnets in the existing tunnel?

Answer: The only firm future plans at CERN are related to Phase II of the Large Electron-Positron, LEP, facility, which is to upgrade the energy of LEP to the 100-120 GeV per beam range. This upgrade is planned to immediately follow Phase I which will be completed in 1989. Considerations of future facility construction at CERN beyond Phase II of LEP, including the possibility of a hadron collider using superconducting magnets in the LEP tunnel are being studied by a European committee which is not expected to report its results until 1987. It is premature to speculate on what CERN might decide to do.

Question: Are there other plans for major new high energy physics facilities (aside from Stanford and DESY)?

Answer: There are no plans for a major new high energy physics facility at Stanford beyond the Stanford Linear Collider, SLC, which is currently under construction. The Stanford Linear Accelerator Center, SLAC, is pursuing, at a modest level, generic advanced accelerator R&D studies to investigate a number of promising new accelerator technologies one or more of which might make possible a new generation of accelerators in the next century. At this time, there are no specific facility plans. A High Energy Physics Advisory Panel, HEPAP, subpanel recently studied the U.S. advanced accelerator R&D progress and concluded that these new concepts, although promising, would not be ready to be incorporated in a facility for 15-20 years. A Jason Study reached essentially the same conclusion. I would like to submit a copy of the HEPAP Subpanel report for the record. Elsewhere in the world, besides CERN which I just discussed and DESY which you mentioned, the only other firm accelerator plans are related to the UNK facility under construction at Serpukhov in the Soviet Union. UNK is planned ultimately to provide a 3 TeV fixed-target facility and a 3 TeV per beam proton-proton collider in the early to mid-1990's.

(NOTE: The information referred to was placed in the subcommittee files.)

QUESTIONS SUBMITTED BY SENATOR JOHNSTON

International Cooperation on Physics Accelerators

Question: The cost of building new accelerators has reached several billion dollars. One way to cope with such costs is sharing the cost of new accelerators with other countries. What is DOE's goal, in terms of international competition, in high-energy and nuclear physics (leadership, maintain a competitive position. .)?

Answer: The Department's goal is for the U.S. to maintain a world-competitive position in high energy and nuclear physics. It is important in basic research activities like high energy physics and nuclear physics that the program be of highest quality and have the capability and opportunity for discovering new insight and breakthroughs in understanding. This requires that the U.S. program have world-competitive capabilities and that some of the worldforefront facilities be located in the U.S.

Question: What are the constraints limiting greater international cooperation and cost-sharing? How many of those constraints result from the competitive nature of international physics programs?

Answer: The constraints are largely political and economic. It is difficult enough to get political, scientific, and budgetary agreement on large new facilities in a single country. Getting simultaneous agreement from several countries is much harder. Fortunately, in high energy physics there is a long and substantial history of successful international cooperation on experimental facilities. A new model for international collaboration on high energy accelerator facilities is given by the construction of the Hadron-Elektron-Ring-Anlage (HERA) at DESY (Hamburg, Germany). The German government made a commitment to the construction of this facility, and international participation in this construction was then successfully sought from other countries. The international participation by other countries is in the form of providing technical hardware needed for the faculity. For example, Italy has agreed to supply half the superconducting dipole magnets. With the German government first committing to the project, the problem of obtaining simultaneous agreement from several countries was avoided. Successful high energy physicists and institutions are highly competitive within the country and within a laboratory, as well as internationally--they strive hard to excel. Nonetheless, there is also an excellent spirit of cooperation between both individuals and institution's for the advancement of the science, resulting in a spirit of openness and cooperation in the field. For example, the new antiproton source at Fermilab that is part of the Tevatron I project benefited immensely from the earlier experience at CERN which was freely made available to Fermilab which also benefited from direct ideas and contributions from Soviet physicists. In turn, CERN is now benefiting from the new ideas, modifications and techniques developed by the Fermilab in improving the CERN source. In order to maintain a strong, forefront program, it is recognized that each major world region must maintain frontier experimental capability. Worldwide coordination

and cooperation is in place to ensure that these large facilities are complementary, rather than duplicative. It should be noted that it has been formal practice for many years throughout the world of high energy physics that unique forefront accelerators in one area provide beam free of charge to scientists on the overall scientific merit of their proposals and without regard to nationality. Thus, U.S. scientists are using unique European and Japanese high energy physics facilities without charge for beam time and vice versa.

Question: What has DOE achieved in terms of international cost-sharing arrangements?

Answer: Major world facilities both in the U.S. and abroad are available to scientists of all nations based on the scientific merit of their proposals and without charge for beam. This mutually beneficial access to foreign facilities which have unique capabilities not available in the home region constitutes a major form of international cost sharing. There is also substantial cost-sharing in the fabrication of large experimental facilities. To pick two recent major examples, the Japanese and Italians have contributed substantially to the Collider Detector at Fermilab (CDF), in excess of $12.5 million and $5.0 million, respectively. Meanwhile, the U.S. is contributing about $24 million of equipment toward the collaborative LEP-3 detector for use at the CERN Large Electron-Positron collider. The cost sharing with Japan and the Soviet Union is covered primarily under formal agreements of cooperation between governments, while that with Western Europe is arranged on a less formal laboratory-laboratory basis.

Question: Electron and proton accelerators have often been used to explore similar areas of physics. For example, the J/PSI particle was independently discovered at SPEAR (a collider) and at the Alternating Gradient Synchrotron (a proton accelerator). If both electron accelerators and proton accelerators are capable of exploring the same areas of physics, are we funding duplicative machines?

Answer: No, we are not funding any duplicative machines. Each machine that is built has unique capabilities where it alone can function and is complementary to the others. This uniqueness may reside in the mass region it covers, the type of process it probes, or some special characteristics of its beams. There are

many areas of physics that can only be probed by one type of machine. In addition, there are some areas of physics which can be accessed by more than one machine. However, in these cases, the electron and proton machines access the physics with different probes and provide complementary, not duplicative, information. The discovery of the J/psi is a good example of this complementarity. While the Alternating Gradient Synchrotron, AGS, was a good machine for discovering this particle, it was a very poor machine to do follow-up studies to ferret out the detailed properties and broader implications of the J/psi. On the other hand, the SPEAR collider, using a different probe, was a difficult machine on which to initially discover the J/psi but was ideally suited for

the followup studies.

The fact that both discovered the J/psi provided important and essential confirmatory evidence for such a major breakthrough.

Question: If both types of machines are required, but both machines can explore the same physics areas, why must the U.S. build both types (SLC is an electron accelerator, FERMI and SSC are proton accelerators) when the Europeans are also building both types (LEP is an electron accelerator and there are plans to install a proton accelerator in the LEP tunnel)?

Answer: The existing or planned world machines which you mentioned all have different capabilities for research and complement each other; in general, they explore different physics areas. With regard to the SLC and LEP electron-positron colliders, there is some overlap, but we must recall that SLC is justified as an accelerator technology study as well as a physics research facility and that both LEP and SLC have unique physics capabilities that do not overlap. SLC can operate with polarized beams, and because of its very small beam size, is ideal for searching for decays of short-lived objects. SLC will provide a critical technical test of the feasibility of future large linear colliders, while LEP employs conventional circular collider technology. While LEP can explore the same energy domain as SLC, it can also go to much higher energies than SLC and is expected to operate most of the time at energies of 60 GeV and above compared to the 50 GeV limit for SLC. Let me now turn to the proton colliders, Tevatron, SSC, and that talked of for the LEP tunnel at CERN. The Tevatron collider explores with 1 TeV per beam the 100-200 GeV mass range, by means of quark-quark and quark-gluon collisions. SSC with 20 TeV per beam would explore the TeV mass range which is clearly inaccessible to any other accelerator existing or planned. Thus, their energy domains are quite different. As for possible overlap with European facilities, I would note that Europe is still studying its future plans, including the possibility of a hadron collider in the LEP tunnel. The results of their study are expected in 1987, but there are no firm plans yet for other than completion of Phase II of LEP. This upgrade to follow immediately after Phase I, will raise the energy of LEP to 100-120 GeV per beam. If Europe decides to proceed with a hadron collider, their collider using today's superconducting magnet technology would have an energy of at most 5.5 to 6 TeV per beam and would suffer the limitations of having to share the tunnel with LEP, an important world class facility itself.

Utilization of Physics Facilities

Question: DOE has estimated that the utilization of its accelerator facilities is currently less than 50 percent. What factors have limited the utilization rates at the high-energy physics facilities?

Answer: Obviously the available funding is a prime factor which determines the total operating time of a facility during a given year. In some cases, there are also technical limitations on the various programs at each laboratory. For example, the Fermilab Tevatron can operate either for fixed-target experiments or for colliding beam experiments, but not both simultaneously. Thus, as

we begin research in FY 1987 with the collider within an overall operating schedule slightly less than in FY 1985, the amount of operating for fixed-target research in FY 1987 will be substantially reduced from the FY 1985 level. In other cases, there are necessary long shutdowns for construction-related activities or major reorganization of experimental facilities. In FY 1986, SLAC was off the air for substantial time, and Fermilab almost totally, because of construction-related shutdowns, collider commissioning, and the Gramm-Rudman-Hollings reductions. There are also external situations such as the special summer power problems at SLAC where extremely large power rate premiums and vulnerability to unscheduled power outages make operation unfeasible and very expensive.

Question: What does DOE consider to be the optimal utilization rate for each of its physics accelerators? What is this rate based on?

Answer: We consider the practical maximum utilization of an accelerator facility to be the maximum number of weeks per year that the facility could be operated taking into consideration necessary downtime for maintenance, holiday periods, need to rearrange experimental configurations, the need to commission new beam lines, and special electric power stituations such as the summer power limitation at SLAC. We estimate that the practical maximum utilization would be 48 weeks out of 52 for Fermilab, 44 weeks for AGS, and 40 weeks for SLC. Optimal utilization, on the other hand, is defined to be the maximum cost-effective utilization of a facility, taking into account the overall cost-effectiveness, balance, and productivity of the total program at the laboratory. Optimal utilization is estimated to be 70-80 percent of the practical maximum depending upon the particular circumstances with the accelerator and experimental facilities in a given year.

Question: How do the utilization rates at DOE's physics facilities compare to utilization rates at foreign physics facilities?

Answer: The foreign facility most similar to Fermilab is the European Laboratory for Particle Physics, known as CERN, located near Geneva, Switzerland. During CY 1985, CERN operated its Super Proton Synchrotron, SPS, about 15 weeks for fixed target physics and another 21 weeks for the colliding beam research program. This totals 36 weeks of operation for physics research out of a 48 week practical maximum, or about 75 percent utilization. During FY 1985, Fermilab's Tevatron was operated for about 30 weeks for fixed-target physics, which is a utilization rate of about 62.5 percent.

The foreign laboratory most comparable to SLAC is the Deutsches Elektronen Synchrotron, DESY, in Hamburg, West Germany. DESY'S PETRA collider is similar to SLAC's Positron-Electron Project, PEP, collider, and their DORIS II collider is comparable to SLAC's Stanford Positron Electron Asymmetric Ring, SPEAR, collider, although in both cases the DESY colliders are capable of