Ion Pair Yields in the X-Ray Decomposition of Hydrogen Bromide in Rare Gas Atmospheres

The rate of x-ray induced decomposition of hydrogen bromide has been measured both in the pure gas and in rare gas atmospheres. The rate of ion pair formation under identical irradiation has been determined from the saturation ionization currents in rare gases and ion pair yields for decomposition of hydrogen bromide have been computed. Average yields were A–HBr, 4.7; Kr–HBr, 4.0; Xe–HBr, 4.7; HBr, 4.6; HBr–Xe, 5.2; where the first substance named is the major component. A mechanism for decomposition by ion formation accounts for a yield of 4.0. Values above this are attributed to dissociative excitation without ionization.