Ion Yields and Fragmentation Processes in the Radiolysis of HCl and DCl

The ionization yield from fast electron impact on DCl under radiolysis conditions at 200 to 650 Torr was found to be 1.006 ± 0.023 times that from HCl. Also primary ionization processes were investigated by mass spectrometry. The relative abundance of Cl+ from HCl near threshold at 17.4 eV was about twice that from DCl, but processes with onset at and above 21.0 eV did not exhibit an isotope effect. The interpretation of the results and their implications concerning the mechanism of radiolysis of HCl were discussed.