Electron loss by 1-300 keV H⁻ions in H and H₂

Cross sections sigma 10 - and sigma 11 - for one- and two-electron loss by 1-300 keV H - ions in H and H 2 have been determined by using a tungsten-tube furnace to provide a target of highly dissociated hydrogen. The only previous experimental studies of H - -H collisions by Hummer et al (see Phys. Res., vol.119, p.668 (1960)) are shown to be in good accord with the present data which are also compared with a number of theoretical estimates.