MASS-RESOLVED 2-PHOTON AND PHOTOELECTRON-SPECTRA OF XE-2 IN THE XE(4F) REGION ABOVE THE FIRST MOLECULAR IONIZATION LIMIT

Two-photon resonance enhanced multiphoton ionization (REMPI), time-of- flight (TOF) mass spectrometry, and photoelectron spectroscopy have be en used to investigate the gerade Xe-2 Rydberg states located just abo ve the first molecular ionization limit. Effective vibrational analyse s are presented for live dimer states that dissociate to Xe+Xe(4f). T he electronic symmetries of the band systems in this region were deduc ed from separate REMPI spectra recorded with linearly and circularly p olarized laser light while excited state bond lengths were estimated f rom Franck-Condon intensity simulations. Two photoelectron signals wer e measured for each molecular resonance examined in this work. The str ongest one, having a near zero kinetic energy, is attributed to dimer electrons released through autoionization. The weaker photoelectron si gnals corresponding to faster electrons originate from excited state X e atoms formed by predissociation. (C) 1998 American Institute of Phys ics. [S0021-9606(98)00732-6].