The development of high-perveance electron-optics on the basis of longitudinal compression

The development of high-perveance electron-optics is examined with particular emphasis on the concept of longitudinal charge compression and the implementation of this concept in electron-optical devices. Analytic formulas for the quantitative relations are presented, and several high-perveance electron guns with longitudinal compression are described. Attention is given to applications of high-perveance guns, with particular reference to the operation of a high-vacuum ion source, a high-intensity soft-X-ray tube, an electrovacuum frequency multiplier, and a low-voltage electron-optic evaporative device.