SLAC, Menlo Park, California, USA
Stanford University, Stanford, California, USA
We report on the development of a cryogenic X-band (11.424 GHz) accelerator to provide electron beams for Very High Energy Electron therapy. The distributed coupling linac is designed with a 135° phase advance, capable of producing a 100 MeV/m accelerating gradient in a one-meter structure using only 19 MW when operating at 77 K. This peak power will be achieved through pulse compression of a 5-8 MW few-µs pulse, ensuring compatibility with a commercial power source. We present designs of the cryogenic linac and power distribution system, as well as a room temperature pulse compressor using the HE11 mode in a corrugated cavity. We discuss scaling this compact and economical design into a 16 linac array that can achieve FLASH dose rates (> 40 Gy/s) while eliminating the downtime associated with gantry motion.
SLAC, Menlo Park, California, USA
Dymenso LLC, San Francisco, USA
Euclid TechLabs, Solon, Ohio, USA
We will present a physics design of a compact, highly efficient, energy-tunable linac to generate up to 500 W of 10 MeV electron beam power for medical and security applications. This linac will employ a patented travelling wave accelerating structure with outside power flow which combines the advantages of high efficiency with energy tunability of traveling wave cavities. Unlike standing wave structures, the proposed structure has little power reflected back to the RF source, eliminating the need for a heavy, lossy waveguide isolator. In contrast to the side-coupled cavity designs, the proposed structure is symmetrical and therefore it does not have deflecting axial fields that impair the beam transport. The high shunt impedance will allow the linac to achieve an output energy of up to 10 MeV when powered by a compact commercial 9.3 GHz 1.7 MW magnetron. For pulse-to-pulse tuning of the beam output energy we will change of the beam-loaded gradient by varying the triode gun current.