Development of a 20 MeV Dielectric-Loaded Accelerator Test Facility

This paper presents a progress report on a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the Stanford Linear Accelerator Center (SLAC), to develop a dielectric-loaded accelerator (DLA) test facility powered by a high-power 11.424-GHz magnicon amplifier. The magnicon can presently produce 25 MW of output power in a 200-ns pulse at 10 Hz, and efforts are in progress to increase this to 50 MW. The facility will include a 5-MeV electron injector that was developed by the Accelerator Laboratory of Tsinghua University, Beijing, China. The DLA test structures are being developed by ANL, and some have undergone testing at NRL at gradients up to ∼ 8 MV/m. SLAC is developing a means to combine the two magnicon output arms, and to drive an injector and accelerator with separate control of the power ratio and relative phase. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year. The initial goal is to produce a compact 20-MeV dielectric-loaded test accelerator.