Secondary Electron Yield from an Al Surface Bombarded by 20–80 keV Ar⁺Ions

Abstract

A secondary electron yield from a polycrystalline Al surface was measured under Ar þ bombardment. The yield of negatively charged particles ðÞ was measured as a function of steady state oxygen coverage of target surfaces during Ar þ bombardment. Projectile energy was changed from 20 to 80 keV. The absolute value of effective oxygen coverage of a target surface was determined in situ by means of an optical spectroscopic technique in which light intensities emitted by sputtered excited atoms from the target was measured as a function of current densities of the projectile. Absolute yield of secondary electrons at zero oxygen coverage, ð0Þ, was obtained by measuring yield variation as a function of .