Electron Detachment from the Negative Hydrogen Ion by Electron Impact

The Born-Oppenheimer approximation has been used to evaluate the cross section for the detachment of electrons from H - by electron impact over an energy range from threshold (0.75 eV) to 75 eV. An empirical correction was then applied to account approximately for the long range Coulomb repulsion between the incident electron and the negative ion. The resulting cross section has a broad maximum of 700π a 0 2 centred at about 45 eV.