Smooth magnetic cusp profile calculation for axis-encircling electron beam generation

Abstract

The calculation method of a smooth magnetic cusp profile has been introduced to obtain an axis-encircling electron beam in a fixed electrostatic field distribution. Using the calculated smooth magnetic cusp profile, an axis-encircling electron beam of current 1 A and voltage 30 kV can be obtained with a velocity ratio 1.8 and low beam ripples. Theoretical calculation and 3D simulations agree well, which show that this method can be widely used in other axis-encircling electron gun designing.