Temperature effect on the ionization potential line-shape of NO doped into dense gaseous argon

The field ionization spectrum of NO doped into dense gaseous argon (ϱ = 1.80 × 1021 cm−3) was obtained at two temperatures, 298 and 158 K. The ionization potential line-shapes obtained for the low temperature sample were found to be wider and to extend further to the red than the high temperature ones. This behavior was also found in the polarization energy distributions calculated using Monte Carlo techniques. Excellent agreement was found between the experimental ionization line-shapes and the ones obtained by convoluting the field ionization spectrum of pure NO with the polarization distributions.