Source for intense coherent electron pulses

摘要

A source for intense coherent electron pulses of an energy below 1 keV comprises an ultrasharp electron-emitting tip and an anode both arranged in mutual alignment inside a vacuum envelope A pulsed potential with an amplitude in the range between 100 V and 500 V and with a variable pulse rate is applied between said tip and said anode. The tip is maintained negative with respect to said anode, the tip having a sharpness such that the electric field at its surface exceeds 10.sup.7 V/cm at said pulsed potential.