Heating and diffusion of hot electrons in non-polar liquids

Abstract

The drift velocities of excess electrons in liquid Ar, Kr and Xe under strong heating fields (up to field strengths of about 106V cm-1), their mean energy, longitudinal and transverse diffusion coefficients and respective characteristic energies are calculated in the framework of the Lekner-Cohen theory (1967). Computed values of the characteristic transverse energy are considerably greater than the mean electron energy and attain a few tens of eV. The transverse diffusion coefficient is larger than the longitudinal coefficient by a factor of a hundred. These effects are caused by the sharp increase of the structure factor of liquids for wavenumbers corresponding to energies of a few eV. The behaviour of the structure factor is also responsible for the non-monotonic behaviour of the electron drift velocity as a function of the electric field strength. The results of these calculations are compared with available experimental data.