The electronegative character of a reflex discharge source operating in hydrogen

In this paper attention is focused on the possibility of obtaining a high production of negative hydrogen ions H − within the volume of a nonequilibrium reflex discharge plasma for gas pressure levels from 0.1 to 10 Pa. To obtain the best values for both the negative hydrogen ion density n − and the negative ion fraction n − / n e the operating conditions are optimized as a function of pressure, discharge power, and magnetic field. The experiment shows that the reflex discharge steady-state plasma is uniform for a dissipated power P = 400 W and has the best efficiency within the pressure range from 0.5 to 2.0 Pa, where the negative ion density is almost 10 17 m −3 , and the negative ion fraction n − / n e is almost 2.5%.