Simulating accelerator structure operation at high power

Abstract

The important limiting factors in high-gradient accelerator structure operation are dark current capture, RF breakdown and electron multipacting. These processes involve both primary and secondary electron field emission and produce plasma and X-rays. To better understand these phenomena, we have simulated dark current generation and transport in a linac structure and a square-bend waveguide, both high power tested at SLAC. For these simulations, we use the parallel, time-domain, unstructured-grid code T a d P and the particle tracking module Track3P. In this paper, we present numerical results and their comparison with measurements on energy spectrum of electrons transmitted in a 30-cell structure and of X-rays emitted from the square-bend waveguide.

Decomposition Method for Complex 3D Problems in Electron Optics

“…2 and 3. The goal of simulation was study of dark currents in accelerator structure [1,2], when the cold emission from the walls at high field gradients further produces the cascades of secondary electrons shown at Fig. 4.…”