The design of a small-orbit/large-orbit gyroklystron experiment

Abstract

Detailed here are the characteristics of the designs of a 500-kV, 45-A electron gun and two 10-GHz gyroklystron circuits. The electron gun produces a rotating beam by passing an annular, linearly streaming beam through a nonadiabatic magnetic transition followed by an adiabatic-compression region. It is demonstrated that the same gun can produce either a small-orbit beam suitable for interaction with a TEo01 cavity mode or a large-orbit beam suitable for interaction with a TEo31 cavity mode. A detailed comparison of the relevant circuit characteristics, including peak gain and efficiency, performance degradation with increasing velocity spread, and AM and PM sensitivities to voltage and current fluctuations, is made.

The axially modulated, cusp-injected, large-orbit gyrotron amplifier

“…A major disadvantage of fundamental mode operation at high frequency is the requisite (large) applied magnetic field and the accompanying material bulk and/or power consumption. The idea of using rotating e-layers, i.e., large-orbit beams with zero guiding center radii, to reduce the magnetic field requirement via high-harmonic operation has received a fair amount of attention in the past few years both experimentally [5]-[ 151 and theoretically [ 161- [23]. The required field is inversely proportional to the harmonic number, m, and thus the coil power is generally inversely proportional to m2.…”