An Inexpensive High-Current Betatron Using Fixed-Field Alternating Focusing and New Low-Loss Magnetic Materials

75621S Electron sources in the commercially important 5 to 20 MeV energy range are limited. These sources are used not only for the testing of advanced accelerator components but also for cancer treatment, medical device and mail sterilization, food irradiation, and plastics processing. Radio-frequency linear accelerators are the industry standard, but they are complicated and expensive. Betatrons hold the promise of being much simpler and less expensive, but previously they were limited to very low currents. This project will employ Fixed-Field-Alternating-Gradient focusing to increase the current capability of the betatron. Modern advances in low-loss magnetic materials also will be applied to increase the repetition rate. In Phase I, the focusing lattice was optimized, collective effects were examined to determine the stability limits, field magnets were designed, a betatron core power supply schematic was generated, and other hardware issues were addressed. The result of these activities is a robust, efficient, and extensive design for prototype fabrication. In Phase II, the field magnets, vacuum chamber, and diagnostics systems will be custom fabricated. Other major systems (the betatron core, power supplies, injector) will be purchased. Finally, the components will be integrated, and the accelerator will be commissioned to 6 MeV and more than 1 mA average current. Commercial Applications and Other Benefits as described by the awardee: A 6 MeV, high power, inexpensive electron source should find application in a number of markets: the well-developed medical-products-sterilization industry would readily adopt a less expensive technology; cargo inspection is a rapidly growing application of high-power accelerators, and reduced costs would allow the equipment to be more widely used at port facilities; the use of this device for mail sterilization would fit within the budget of every large postal facility in the country; radiation cancer treatment would be made considerably less expensive, making this life-saving treatment more available in developing nations.