Measurements and calculations of the anomalous energy broadening of a 300-eV electron beam

Abstract

Measurements and calculations of the energy full width at half maximum (FWHM) of a 300-eV electron beam are presented as a function of current. The measurements utilize a low-energy telefocus electron gun and a 127° cylindrical energy analyzer. The calculations combine theories of Knauer and Zimmermann with beam envelope determinations obtained from a combination of electron ray tracing and measurements on the beam. The energy width is numerically integrated along the beam envelope, and the FWHM is calculated. The calculations agree in magnitude with the measurements, but there is a discrepancy in the current dependence.