Partial photoionisation cross section measurements for atomic cadmium and mercury

Measurements have been made on the partial photoionisation cross sections of cadmium (19-30 eV) and mercury (15-35 eV), using the technique of photoelectron spectroscopy and synchrotron radiation from the 5 GeV electron synchrotron NINA. The 2 D 5/2 : 2 D 3/2 branching ratios for both cadmium and mercury deviate from the statistical ratio as a function of photon energy, in agreement with recent theoretical calculations; the deviation is greater in the case of mercury, demonstrating the increased importance of relativistic effects.