Design of a Triodelike Electron Gun for Millimeter-Wave Gyrodevices

A computational study has been made on the design of a 150-kV triodelike switchable electron gun. A smooth magnetic cusp arrangement was used to produce an axis-encircling beam. Numerical optimization of this arrangement led to a gun design that produced beam parameters of
$I_{b} \sim \hbox{6}\ \hbox{A}$
,
$\alpha = \hbox{1.2}$
, and
$d\alpha \sim \hbox{15}\%$
. It has also been shown that this triode design can produce beam suppression at
$\sim$
2 kV while not interfering with the beam parameters under operation conditions.