DETERMINATION OF THE CONDUCTION-BAND ENERGY MINIMUM IN FLUID ARGON BYMEANS OF FIELD-IONIZATION

The evolution of the ionization potential of H2S doped in argon for ar gon densities between the dilute gas and the triple point liquid was o btained by means of field ionization. The field ionization spectra of H2S in argon were simulated by convoluting the spectrum obtained in pu re H2S with the calculated polarization energy distribution between th e H2S ion and the medium. The density dependence of the conduction ban d energy minimum V-0(rho) (relative to vacuum) was obtained from the e nergy difference between the experimental spectra and the simulations. Excellent agreement was found between these values and those obtained using a larger molecule, CH3I. The values of V-0(rho) are compared to recent theoretical calculations. (C) 1996 American Institute of Physi cs.