Study of moving striations in plasmas. IV. Electron-energy transfer and the determination of the electron thermal relaxation length

Abstract

A general expression relating the small variations of the electron density, the electric field, and the electron temperature in a positive column is derived. It is shown that measurements of the variations of these plasma parameters in moving striations of small amplitude and in particular of the relative phase of these variations can be used to determine the thermal relaxation length for the electrons in a positive column.The value of the electron thermal relaxation length for a positive column in neon, with a pressure of 1 Torr, discharge current 26 mA, discharge-tube diameter 6.5 cm, is found to be approximately 1 cm.