Time- and Space-Focusing Detector System for Real-Time Electron Beam Testing

Abstract

A new real-time detector system which enables time resolution in the picosecond region is proposed. The system combines the principle of time- and space-focusing actions and the operating principle of the streak tube. Secondary electrons extracted by high voltage are focused in time onto the center of a sweeping deflector and are focused in space onto the screen. Two models are designed in the first-order approximation. One model utilizes an electrostatic toroidal sector field which has simultaneous time- and space-focusing properties. The other model uses a retarding field for time focusing and electrostatic lenses for space focusing. The analyzed results in both models show that the time resolution of about 5 ps can be realized. The collection efficiency of emitted secondary electrons is in the order of 10-2.