Excess electron mobility in high-density argon gas

Abstract

We report accurate measurements of excess electron mobility in high-density Ar gas at a temperature T\ensuremath{\simeq}163 K in the density range (4N70)\ifmmode\times\else\texttimes\fi{}${10}^{20}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$ as a function of the electric-field strength. The positive-density effect shown by the zero-field density-normalized mobility ${\mathrm{\ensuremath{\mu}}}_{0}$N can be explained within the same theoretical framework recently used for neon gas, where ${\mathrm{\ensuremath{\mu}}}_{0}$N shows a negative-density effect. Thus the analysis of our present measurements indicates that there is no need for two separate theories for both negative- and positive-scattering-length gases.