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

75621-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, physics and engineering issues will be addressed to optimize the beam current and minimize the cost. A 5 MeV machine with greater than 1 mA of average current will be designed. A complete set of drawings and schematics and material selection will be completed for the prototype, which will be built in Phase II. Commercial Applications and Other Benefits as described by the awardee: A 5 MeV, high power, inexpensive electron source should find immediate and eager markets: the medical products sterilization industry already is well developed; mail sterilization with this device would fit within the budget of every large postal facility in the country; it would have application in the growing food irradiation industry; many plastics manufacturers incorporate radiation treatment to improve the quality of some products; and, finally, radiation cancer treatment would be made considerably less expensive, making it more available to third world countries.