Abstract
A study has been made of the optics of an electron beam with a perveance of 10−6 amps/(volt)3/2 constrained by an axial magnetic field. Measurements of the beam contour for different conditions of entry into the field were made with the aid of a screen which could be moved to intercept the beam. Rough measurements of the radial current distribution, and a measurement of the efficiency of transmission through a drift tube, were also made. Fair agreement with theory was found, although there were significant discrepancies which have not been explained.