Two-photon time-of-flight spectra of Xe2

Abstract

Resonantly enhanced multiphoton ionization (REMPI) spectra of jet-cooled Xe2 are presented, covering the spectral region between ≊74 627 and 80 849 cm−1. Dimer ions produced by (2+1) REMPI excitation were mass selected in a linear time-of-flight (TOF) mass spectrometer. The vibrational and isotopic structure of several band systems dissociating to Xe* 5p56p and 5p55d asymptotes have been analyzed, many unambiguously for the first time, and molecular constants derived. Equilibrium bond lengths were estimated from Franck–Condon calculations. Insight into excited state predissociation was also obtained by recording atomic TOF excitation spectra.

Analysis of the mass-resolved two-photon spectra of jet-cooled ArKr near Kr*(5p) and Ar*(4s)

“…The results here and those obtained for the Xe containing excimers [9][10][11][13][14][15] show that REMPI excitation, TOF mass spectrometry, and polarization measurements are a powerful combination for unraveling the complexities of these molecular systems. It is hoped that our data will prove useful in the interpretation of the rates of energy and population transfers between atomic levels in Ar/Kr gas mixtures in terms of avoided crossings between the potential energy curves of the heteronuclear collision pairs.…”

“…Since the experimental arrangement used to record ͑2ϩ1͒ REMPI/TOF spectra of the rare gas dimers has been described fully elsewhere, 9,16 only a brief overview is presented here. ArKr molecules were produced by expanding a 12.5% Kr in Ar mixture at a stagnation pressure of Ϸ6 atm through the 1.0 mm pinhole of a pulsed valve ͑General Valve Corporation, 9-181-901͒.…”

“…To date, our group has provided detailed vibrational analyses of the single isotopomer spectra of Xe 2 , [9][10][11] Kr 2 , 10,12 KrXe, 13,14 and ArXe 14,15 which were recorded using ͑2ϩ1͒ REMPI/TOF experimental methods. We have for most of the transitions considered, also deduced excited state symmetries from separate REMPI/TOF spectra recorded with circularly polarized light, and excited state bond lengths from Franck-Condon factor calculations.…”

Communication: Imaging wavefunctions in dissociative photoionization

“…In fitting to the experimental data, the Xe 2 6p 2 [ 1 / 2 ] 0 0 + g was modeled by a Morse potential and the molecular parameters were fixed to those determined previously. 12,13 The ionic Xe 2 + I( 1 / 2 g) state was assumed to be Morse-like, with the values for D e + (72.9 cm −1 ) and R e + (6.096 Å) being fixed to those determined by Zehnder et al, 20 and ω e + and ω e x e + values optimized for agreement with experimental distributions. It is important to note, however, that only the repulsive wall of this potential is sampled in this study, not any bound region.…”

“…14 The spectroscopy of the Rydberg states of Xe 2 has been explored in detail previously. 12 the g (v , 0) transitions indicate Xe + production via two distinct mechanisms. One results in low fragment kinetic energy release of 0-750 cm −1 and another produces fragments with fKER ≈ 27 500 cm −1 as shown in the momentum space image reconstruction in Fig.…”