Secondary electron emission from insulators

Abstract

The high yield of secondary electron emission from insulators due to electron bombardment may be the result of an increase of the depth of escape. The free-electron scattering theory is applied to the high energy of the primary beam, but it cannot be applied to the low energy of the secondary escaping beam because of the large energy gap of insulators. Then the plasmon loss with the valence electron is considered when the secondary electrons escape. Secondary electron emissions from insulators are calculated from the assumptions that the distribution of the secondary electrons due to both incident and back-scattered electrons within the target is isotropic and that it follows the absorption law of Lenard type. The universal yield-energy curve of secondary electron emission is derived.