Experimental Observations of the Diffusion Cooling of Electrons in Argon

Abstract

The cooling by diffusion of electrons in argon and in argon–hydrogen mixtures has been studied by the Cavalieri density sampling technique. In the case of argon, the measured values of the reduced diffusion coefficient ND varied by more than a factor of two over the pressure range 2–8 kPa. When small quantities of hydrogen were added to the argon, the cooling effect was reduced due to the increased energy transfer between the electrons and gas molecules. For argon, the magnitude and pressure dependence of ND are in satisfactory agreement with the recent calculations by Leemon and Kumar (1975).