Effect of surface alteration of hydride titanium washers on discharge characteristics of plasma gun

Several titanium (Ti) hydride washers containing different amounts of both TiN and an oxide compound (Ox) are tested for the source of hydrogen (H+) plasmas. According to the different-looking surfaces of the washers of Ti hydride, considerable change in the required discharge voltage is observed. Slightly larger probe currents are also measured from plasmas produced with the washers having the smallest amounts of TiN and Ox, which suggests the existence of more H+ ions in the formed plasmas. Once apparent grain coarsening appears on the surface of Ti hydride washers at the temperature around 950°C, no successful electric discharge occurred.