Electron Linear Accelerator for the Pion Therapy

The electron linear accelerator has been designed for the pion therapy. The accelerating structures are of Disk and Washer (DAW) type and cooled by the help of heat pipes. The energy and beam current of the accelerator, are 500 MeV and 400 ¿A, respectively, with a conventional RF system. The length of the linac is about 50 m, which is shorter than those hitherto designed for a similar purpose. Production of the pions and inevitable background radiations, mainly, neutrons and electrons, at the target are optimized. A new cooling technique of the target is suggested. Collection of the pions emitted over about 1 str. is performed by using the superconducting coils of the SMPG and axisymmetric types. About 35 rad. 1/min. is expected at the position of a patient.