Measuring the secondary electron emission characteristic of insulators

A UHV system equipped with a standard LEED/Auger diagnostic has been modified to permit the measurement of the coefficient of secondary electron emission, delta, under electron bombardment. In order to measure the coefficient on insulators, the beam is pulsed. Problems due to charging are alleviated by alternating between pulses in which the target charges negatively (delta < 1) and positively (delta > 1). The measuring technique is demonstrated by means of results obtained on mica and alumina. Residual and intrinsic charging effects are discussed. (C) 2003 Elsevier B.V. All rights reserved.