A high resolution electron spectrometer facility for studying the spectra of microscopically localized field emission sites on planar cathodes

Abstract

A high resolution (≲30 me V) electron spectrometer originally designed for studying micropoint emitters, has been adapted to measure the electron spectra of the microscopically localized field electron emission processes that occur on broad-area high voltage electrodes. Details are given of the redesigned electron optical and mechanical systems, including a new electrostatic interfacing lens and a micromanipulator assembly for scanning the specimen cathode. The performance of the new facility has been evaluated, and its resolution has been estimated to be <80 meV. A micropoint anode probe and an associated image intensifier viewing system has been used for recording the complementary electroluminescent optical emission spectra. Facilities for the in situ treatment of electrode surfaces, viz, electron bombardment heating and ion etching, have also been incorporated and their effect on the emission characteristics of broad-area sites has been investigated.