15min:
PHOTOION-PAIR PRODUCTION IN HF, DF AND (HF)2.

QICHI HU, JOHN W. HEPBURN, Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.

The dissociation processes of HF/DF + h nu rightarrow H+/D+ + F- and (HF)2 + h nu rightarrow HFH+ + F- have been studied through single photon excitation with coherent vacuum ultraviolet light. For HF and DF, the laser was scanned around the ion-pair dissociation energies. The spectra demonstrate that the ion-pair production could be greatly enhanced through the coupling between the ion-pair states and the Rydberg states converging to certain levels of HF+/DF+. The results from our current high resolution study lead to different conclusions than those resulting from lower resolution synchrotron experiments . For the ion-pair production of (HF)2, some preliminary results and possible explanations will be presented.