Parametric computations of electron energy distribution function (EEDF) and
of electron mobility in photoplasma of sodium mixture with different inert
gases are presented. The conditions of a weak external electric field are
considered when electron heating is provided by super-elastic impacts (seco
nd kind collisions) with excited sodium atoms. It is demonstrated that none
quilibrium EEDF arising in heavy inert gases due to Ramsauer minimum on the
cross Section of elastic electron-atom collisions can considerably affect
electron mobility. It results in complex nonmonotonous dependence of electr
on mobility from partial pressure of mixture components, plasma ionization
degree, and from resonant-excited sodium atoms density. In Na + Kr, Na + Xe
mixtures by low plasma ionization degree, the electron mobility can differ
by more than two times from the ode calculated with Maxwellian EEDF, In Na
+ Ar mixture, in certain conditions, the mobility may take on negative val
ues. The critical plasma parameters (sodium excited atoms density, plasma i
onization degree, electric field strength) determining this effect are reve
aled. The influence of nonequilibrium EEDF on electron mobility helps to ex
plain abnormally low conductivity of photoplasma in Na + Ar mixture observe
d earlier in the experiment.