Development of Novel Cold-Cathode Gas-Discharge Electron Beam Gun:An Instrumentation Study

The cold-cathode gas-discharge electron beam gun was developed with our own intellectual property right.The influence of the key variables, including, but not limited to the eb gun structure, materials and property of cathode/anode, focusing-coil, acceleration voltage, and type/flow-rate/"ignition" voltage of discharge gas, on the e-beam properties was theoretically analyzed, numerically simulated with CST software, experimentally evaluated and tentatively discussed for design optimization.As expected, the type and flow-rate of discharge gas significantly affected the lowest "ignition" voltage.The prototyped eb gun, fabricated via design optimization and in trial-and-error method, was repeatedly tested.The common technical problems were discussed; for instance, in long term operation with pure He and/or Ar, the e-beam current decreased, because of erosion-etching of Al₂O₃-layer on Al-cathode; an O₂-addition of 2% was the solution.The self-developed e-source is capable of stably providing a Max e-beam current of 1500 mA and a highest output power of 30 kW.