ENHANCED METHYL-RADICAL PRODUCTION IN AN AR-CH4 PIN-HOLLOW CATHODE-DISCHARGE

A methyl-radical formation is observed to be enhanced in an Ar-CH4 dis charge plasma using a hollow cathode with movable pins inside. In the discharge with pins, high energy electrons in the radial edge region o f the plasma column produce methyl radicals. They diffuse toward the c entral region of the plasma column, increasing their density, where th e electron temperature is so low (congruent-to 0.4 eV) that there occu rs no reaction to decrease the methyl-radical density.