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

抄録

A secondary electron yield from a polycrystalline Al surface was measured under Ar⁺ bombardment. The yield of negatively charged particles γ(θ) was measured as a function of steady state oxygen coverage θ of target surfaces during Ar⁺ bombardment. Projectile energy was changed from 20 to 80 keV. The absolute value of effective oxygen coverage θ 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, γ(0), was obtained by measuring yield variation as a function of θ.