Design and Simulation of a Uniform Focusing System with Sheet Beam Electron Gun

A uniform focusing system and corresponding sheet beam electron gun for a 140 GHz staggered double vane traveling wave tube (SDV-TWT) were exhibited in this paper. The sheet beam electron gun generates electron beam with properties of voltage 25 kV, current 250 mA and beam size of 0.75 × 0.15 mm
²
. Simulation results demonstrate that a low uniform permanent magnetic field (UP) of 3400 Gs could focus the sheet beam in the beam tunnel of 1.6 ×0.24 mm
²
. And the sheet beam could travel 100 mm stably with a transportation rate of 100
^%
, with good shape and laminarity.