Analysis of non-laminar electron beams for high-power microwave tubes

A semi-automatic system for testing electron beams has been developed. It consists of a demountable, bakeable vacuum chamber, which contains the electron gun under test and a motor-driven pinhole target for scanning the electron beam. A minicomputer (Hewlett-Packard 9820) controls the movement of the target, stores the readings from a digital voltmeter in its memory, and later processes those data. This system provides information on the current and transverse velocity distribution in the beam, which can be used to predict its behavior in a focusing system with greater accuracy than previously possible.