High-gradient Millimeter-wave Accelerator on a Planar Dielectric Substrate/011

摘要

We report the first high gradient studies of a millimeter-wave accelerator,employing for the first time a planar dielectric accelerator, powered by means of a 0.5-A, 300-MeV, 11.424-GHz drive electron beam, synchronous at the 8th harmonic, 91.392 GHz. Embedded in a ring-resonator circuit within the electron beamline vacuum, this structure was operated at 20 MeV/m, with a circulating power of 200 kW, for 2x10-5 pulses, with no sign of breakdown, dielectric charging or other deleterious high-gradient phenomena. We also present the first measurement of the quadrupolar content of an accelerating mode.