Thermionic heater cathode electron-beam gun - has gun cathode near metal ribbon filament with W=shaped thermionic portion

摘要

Thermionic heater cathode assembly for an electron beam gun, comprises a disc cathode made of a highly-emissive material and disposed near a metal ribbon filament the thermionic portion has a W shape. The distance between two apices of the thermionic portion is 0.6 to 0.8 of the disc cathode dia. and the depth of the valley between the apices constitutes 0.5 to 0.6 of the dia. The invention provides a means for welding, fusion and other metal working processes relating to electron-beam engineering. The metal ribbon filament permits trouble-free operation in the range 1,800 - 2,000 deg.C for 8 hours. The heating power does not exceed 75 W, and the electron beam gun power is 60 kW.