Kinetic energies and angular distributions of H+ ions produced by electron impact on H+

Abstract An apparatus has been constructed to study the kinetic energies and angular distributions of ions produced by electron impact on gaseous molecules. Results are presented for positive ions produced from hydrogen molecules at incident electron energies of 30–75 eV. The H + kinetic energy data indicate dissociative ionization via the two lowest states of H 2 + along with strong contributions from other mechanisms. The H + angular distributions are anisotropic, peaking in directions parallel to the electron beam and with the degree of anisotropy depending on the electron energy and the ion kinetic energy. The present results are compared with previous studies and found to be in general agreement and to reaffirm the need to consider a variety of H + -producing mechanisms.