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--> C Beam Sources. U.S. Facilities Alternating Gradient Synchrotron, Brookhaven National Laboratory, Upton, New York The Alternating Gradient Synchrotron (AGS) is a high-energy machine used for physics research: 1H up to 30 GeV, heavy ions up to 10 GeV per nucleon. One beam line is available for NASA-sponsored research, when high-energy physics is not in progress. In 1995, 1 GeV/nucleon was available. The AGS delivers 56Fe at 1–10 Gy/min, 100 hr of irradiation time (cost: ~ $350,000). Booster Facility This is a relatively small circular accelerator that injects pulses of heavy ions into the AGS. It is capable of sequentially delivering independent alternate pulses of different ions for two applications such as high-energy nuclear physics and radiation biology. Brookhaven proposed the construction of a separate beam line—the Brookhaven Applications Facility (BAF)—off the Booster, to be used for radiobiology and physical dosimetry of HZE particles. The proposal was reviewed and approved in 1991 by a panel with representatives from NASA and DOE. The proposed BAF would include a switching magnet and focusing magnets that could abstract ion pulses from their circular orbit into a to-be-constructed straight beam line and irradiation room suitable for biological applications and physical studies of energy loss and spallation products from HZE particles traversing shielding material. The BAF would supply reliable beam delivery, guaranteed by the need to maintain all the systems in good operating condition for the main mission of the facility (injection of AGS), and eventually of the Relativistic Heavy Ion Collider. A large variety of HZE particles can be produced ranging from maximum energies of 1.5 GeV/nucleon for ions lighter than iron, to ~ 1.25 GeV/nucleon for iron at ~ 70 Gy/min on 10 cm2, and to ~ 350 MeV/nucleon for gold. The construction cost is estimated to be $18.7 million, and the annual operating costs would be about $4 million for 2,000 hr/yr, in FY 96 dollars. Other Facilities Extensive animal and cell culture facilities exist in the Medical and Biology departments. Housing is available on the site.
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--> National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan The National Superconducting Cyclotron Laboratory is primarily a user facility for experimental physics research using protons and heavy nuclei at energies from ~ 0.2 GeV/nucleon for protons through O and decreasing to 0.07 GeV/nucleon for Fe. The facility is not set up for radiobiology and the energies are too low to be useful for many of the research strategies suggested in the main text of this report, but the facility could be used for some physics that would be of interest to NASA. 88-inch Cyclotron, Lawrence Berkeley National Laboratory, Berkeley, California. The 88-inch cyclotron is used primarily for physics research using protons and heavy ions up to Ne, at energies up to 0.3 GeV/nucleon. For heavier ions, the energy per nucleon decreases with increasing mass. Fundamental radiobiology experiments can be carried out at this site, but the energies are too low to be useful for many of the research strategies suggested in this report. Proton Therapy Facility, Loma Linda University Medical Center, Loma Linda, California The primary mission of the Loma Linda facility is cancer therapy, using protons with energies up to 250 MeV. Eight beam lines enter five shielded rooms. Three of the lines enter one room, where they are used for biological, physical, and engineering studies. The facilities are excellent and are currently used by NASA for up to 400 hr/yr, during the times that therapies are not in progress. This facility would be useful for experiments studying solar events, but not for those studying the effects of protons in the 1-GeV range. LAMPF, Los Alamos National Laboratory, Los Alamos, New Mexico Protons at 850-MeV are available in a parasitic mode from the LAMPF facility, which is used for physics research and radioisotope production. Although the energy range is useful, the radiobiology and animal facilities are not as extensive as those at Brookhaven National Laboratory, and LAMPF's long-term future as a research facility is not assured. Northeast Proton Therapy Center, Massachusetts General Hospital, Boston, Massachusetts The Northeast Proton Therapy Center facility is now under construction, with operation expected in 1998. A cyclotron will deliver 235-MeV protons to three treatment rooms (total budgeted cost, $46 million). There are no provisions, at present, for radiation biology. Cyclotron, University of California at Davis, Davis, California At the cyclotron at the University of California at Davis, 4- to 70-MeV protons may be used for radiobiology, but the research facilities and energies do not compare to those at Loma Linda. Other Proton Facilities Other U.S. facilities for physics research run at energies that overlap those described above but have not been adapted for radiation biology.
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--> Facilities in Other Countries Heavy Ion Medical Accelerator, National Institute of Radiological Sciences, Chiba, Japan The Heavy Ion Medical Accelerator (HIMAC) consists of a high-energy synchrotron that accelerates nuclei of He, C, Ne, Si, and Ar from 100 to 800 MeV/nucleon in three treatment rooms at dose rates up to 5 Gy/min, and four experimental rooms, one of which is for radiation biology. The treatment rooms are used during the day, while the experimental rooms are used during the night. Fe beams are not available at present but may be available in a few years. Conventional radiation (x ray, gamma ray) sources and extensive animal and tissue culture facilities are readily available at HIMAC. If Fe beams became available at this facility and appropriate agreements were developed, the HIMAC could present a viable option for NASA to acquire more of the beam time needed to perform the research recommended in the main text of this report. Such an approach would also require the establishment of appropriate animal colonies in Japan, collaborative efforts with a number of Japanese investigators, and numerous sojourns by U.S. investigators to help coordinate efforts. SIS Accelerator, Institute for Heavy Ion Research (GSI), Darmstadt, Germany The SIS accelerator provides many heavy ions, from Ne to Pb, with energies up to 1 GeV/nucleon. The major emphasis of the facility is physics research. GSI is heavily utilized by national and international research groups, and about 300 scientists and engineers are employed on site. Biology investigators generally can utilize only parasitic beams, and the beam parameters are not usually under the control of biologists. As a result, in vitro experiments can be carried out, but it is very difficult to repeat any of the experiments. There are also significant political problems involved in carrying out animal experiments at this location. In the absence of significant policy changes at this institute, it is unlikely that NASA would be able to utilize it for any of the long-term, repetitious in vitro or animal experiments recommended in the main text of this report. Other Proton Facilities Proton accelerators in Canada and in Switzerland run at ~ 500 MeV for cancer therapy or isotope production. They are not seriously used for radiobiology and have no significant advantages over Loma Linda.
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