Electron Capture Processes in the Hydrogen Halides

The formation of negative ions by resonance capture processes of the type XY+e=X+Y—, has been studied for the hydrogen halides. A monoenergetic electron source has been used and it has been possible to determine the true shape of the resonance capture peaks in these cases. It has been found that the negative ions appear at energies which are in agreement with recent values for the dissociation energies of the H—X bonds, and the electron affinities of the halogen atoms.