High-resolution VUV photoionization spectroscopy of HD between the X2Σ+gv+ = 0 and v+ = 1 thresholds

Publisher Website
Google Scholar
Abstract
The photoionization spectrum of HD has been recorded in the region of the first vibrationally excited level (v+ =1) of the X 2Σ+ g ground state of the HD+ ion using a narrow bandwidth vacuum ultraviolet (VUV) laser. Spectral positions, intensities and line widths are reported for all resonances observed between 126100 and 126700 cm−1. The np Rydberg series converging to the v+ =1, N+ =0 and 2 states of the ion have been observed up to n=150 and used to determine the corresponding ionization thresholds in a multichannel quantum defect theory analysis. After subtraction of the ionic vibrational energy the adiabatic ionization energy of HD was determined to be 124568.491±0.017 cm−1. Several low n interloper Rydberg states converging to higher vibrational levels (v+ >1) of HD+ have also been observed and their interaction with the v+ =1 channel is discussed.