Experimental Investigation of Beam Generation, Acceleration, Transport and Extraction in the RADLAC-II Pulsed Transmission Line Linear Accelerator

摘要

We have investigated the generation, acceleration, transport, and extraction of intense, high-voltage, relativistic electron beams with the RADLAC-II accelerator. A 40-kA, electron beam was produced by a foilless diode injector, which was immersed in, and accurately aligned with, the magnetic axis of a 17-kG solenoidal guide field. The solenoidal field guides the beam through the accelerator, which includes a number of post-accelerating gaps designed to provide radial force balance to suppress radial oscillations. Furthermore, the accelerating cavities have a very low Q and small transverse shunt impedance to suppress beam breakup instabilities. A 70% to 90% transport efficiency was observed, depending on the precision of the beam line alignment. Finally, the beam was extracted, without significant losses, and propagated into a magnetic field-free, air-filled region. (ERA citation 11:038685)