Photoelectron spectroscopy using a supersonic molecular beam source. The2B3u+eminus;larr;1Agtransition in ethylene

摘要

We show that a supersonic molecular beam source will significantly improve the quality of molecular photoelectron spectra by reducing both Doppler and rotational broadening of the target gas, and that the benefits of such a source are realized for spectrometers operating at resolutions of quest;20 meV. The photoelectron spectra of the O2+thinsp;2Pgr;g,vprime;=0+eminus;larr;O2thinsp;3Sgr;gminus;transition in molecular oxygen and the C2H4+thinsp;2B3u+eminus;larr;C2H4thinsp;1Agtransition in ethylene are presented as examples of the technique. Newly resolved vibrational structure in the ethylene spectrum is compared to recent theoretical calculations and to the vibrational structure of the 3sRydberg transition at 1744 Aring;.