ELECTRON-TEMPERATURE AND ELECTRON-DENSITY PROFILES IN ATMOSPHERIC-PRESSURE ARGON PLASMA-JET

Line-shape analysis of the electron feature of Thomson-scattered laser light has been used to directly determine electron-temperature and el ectron-density profiles of an atmospheric-pressure argon plasma jet. M easured center line values of the electron temperature are in excess o f 20000 K at the torch exit, and remain essentially constant with incr easing axial distance even though the plasma is recombining. These res ults are shown to be inconsistent with Saha equilibrium and classical electron-ion momentum transfer theory.