EXPERIMENTAL-STUDY ON AN ELECTRON-BEAM ENERGY RECOVERY-SYSTEM USING AMULTISTAGE COLLECTOR

An electron-beam energy recovery system was experimentally investigate d using a multistage electron collector designed by a numerical simula tion. In our previous experiments, the potential of each electrode was provided through a voltage divider of several hundred megaohms resist ance. Experimentally, it was observed that a part of the beam current was lost to ground through the resistance, and inferred that the elect rostatic effect of the electrodes was changed from the initial operati ng condition. In order to overcome the drawback of voltage divider res istance, two high-voltage power supplies have been provided for the el ectrodes, and the charge collecting electrodes have been kept at a lit tle higher potential than that of the cathode by using a battery. The recovery currents of the system have been directly measured by an amme ter. The maximum charge recovery efficiency of the collector was almos t 100% with a beam current of 0.2 mA. It was, however, seen that this efficiency reduced to 73% for a beam current of about 0.85 mA due to t he secondary emission. The maximum energy recovery efficiency, 74%, wa s calculated for 0.2 mA beam current, and this efficiency was reduced to 58% for a beam current of 0.85 mA. (C) 1998 American Institute of P hysics.