Annular-cathode electron gun for in-line injection in a racetrack microtron

Abstract

A compact annular-cathode electron gun which allows direct, efficient injection into the accelerating structure of a racetrack microtron has been designed, built, and tested. The gun operates under pulsed conditions with applied high voltages of 40 kV or more and delivers an output current in excess of 1 A. Design and construction details are presented for both a basic gun and a gun with built-in output current monitor. Gun performance in a test chamber and in the multicavity racetrack microtron at the University of Western Ontario is described.

Optimization of an electron gun with an off-axis cathode position

“…The latter Another solution may be the use of an annular cathode with a hole at the center for a beam; however, in this case, the beam emittance considerably increases and, as a result, the current loss also increases during the acceleration process [1,2].…”