Laboratory observation of hot bands of H+3

摘要

The (2ngr;2,l=2larr;ngr;2), (2ngr;2,l=0larr;ngr;2), and (ngr;1+ngr;2larr;ngr;1) hot bands of H+3were observed. The vibrationally hot ions were produced in a liquid nitrogen cooled 6 kHz ac discharge using gas mixtures of H2and He. The spectra were detected in direct absorption using a newly extended tunable difference frequency spectrometer using both LiNbO3and LiIO3crystals as nonlinear optical elements. The range of this spectrometer is now sim;5300ndash;sim;1900 cmminus;1. The positions of the rovibrational transitions compare extremely well with the theoretical predictions of Miller and Tennyson. A vibrational temperature study of the discharge indicates a significant population inversion between the ngr;1and ngr;2levels.