Switching and other nonlinear phenomena associated with prebreakdown electron emission currents

An anode probe-hole technique, in conjunction with an electron spectrometer, has been used to study the short-term temporal changes in the emission characteristics of microscopically localised field emission sites on broad-area high voltage electrodes. The observed effects, e.g. the threshold switch-on of sites, and emission mode switching, have been discussed in terms of a new field-induced hot-electron emission model which is based on the concept of dielectric switching through the formation of microscopic conducting channels.