Electron Emission from Nickel-Alloy Surfaces in Cesium Vapor

The cesiated electron emission was measured for three candidate electrodes for use as collectors in thermionic converters. Nickel, Inconel 600 and Hastelloy were tested with a 412°K cesium reservoir. Peak emission from the alloys was found to be comparable to that from pure nickel. Both the Inconel and the Hastelloy samples had work functions of 1.64 ev at peak emission. The minimum work functions were estimated to be 1.37 ev at a probe temperature of 750°K for Inconel and 1.40 ev for Hastelloy at 665°K. The bare work function for both alloys is estimated to be approximately the same as for pure nickel, 4.8 ev.