New microwave source of microdischarges in noble gases at atmospheric pressure

Abstract

In this paper we present a simple and cheap microwave (2.45 GHz) source of microdischarges in argon or neon at atmospheric pressure. The source consisted of a cheap 2.45 GHz microwave magnetron generator and 50 Ω coaxial line terminated with a simple coaxial plasma applicator. The new microwave source of microdischarges operated stable in the form of a small plasma jet at absorbed microwave powers of 9 ÷ 80 W and gas flow rates of 0:5 ÷ 25 l/min. The length and diameter of plasma jets were 1:5 ÷ 14 mm and 0:5 ÷ 1:5 mm, respectively, depending on the kind of gas, gas flow rate and microwave power absorbed by the discharge. The temperature of the plasma jets could be changed from 30 °C to 1 200 °C by changing the gas flow rate or/and absorbed microwave power. The electron density in the plasma jet was around (0:3 ÷ 1:1) × 1015 cm−3, depending on the discharge conditions.