Resonant electron attachment to oxygen molecules in dense helium gas

Abstract

Measurements of the resonant attachment frequency of excess electrons to O2 molecules in dense helium gas have been performed in the temperature range 50-100K. The attachment frequency exhibits a sharp peak at a density NP, which has an unexpected temperature dependence. The peak shape has been simply related to the density dependence of F(ER), the value of the energy distribution function at the resonance energy ER. The results of the experiment indicate that resonant capture by molecular impurities can be used to get unique information on the density of states of a disordered system.