Measurements of Secondary Electron Yield from Materials with Application to Depressed Collectors

摘要

This final technical report reviews the research activities during the period of this grant, emphasizing the final year. The key finding of our study is that the total incident electron dose is a critical parameter affecting secondary electron emission (SEE). A completely automated experimental set-up was implemented that allowed for measurement of secondary electron yield (SEY) as a function of beam energy, angle of incidence of primary electrons, electron dose, and time. We present SEY data for copper, plasma-sprayed boron carbide, and titanium nitride samples with principal attention given to the dose dependence. Experiments were conducted in the energy range 5 - 1000 eV using DC voltages. Modified empirical formulas are proposed that incorporate the dose effect and match the experimental measurements.