ROTATIONALLY RESOLVED SINGLE-PHOTON IONIZATION OF HCL AND DCL

The rotationally resolved photoionization yields of jet-cooled HCI and DCI have been measured in the energy range between their spin-orbit split 2PI ionic thresholds. For single-photon excitation, narrow-band vuv radiation is generated by resonant frequency mixing. The spectra are complex due to an interaction of autoionizing resonances belonging to series converging to different rotational states of the ion core. This is taken into account using the multichannel quantum defect theory in a treatment capable to handle a transition m angular momentum coupling from Hund's case (c) to case (e). Even for Rydberg orders n > 35 the experimental data cannot be explained using a pure case (e) picture.