An atmospheric pressure plasma source driven by a train of monopolar high voltage pulses superimposed to a dc voltage

National Institute for Laser, Plasma and Radiation Physics (INFLPR), 409 Atomistilor St., P.O. Box MG36, 077125 Magurele, Romania

^a e-mail: stoican@infim.ro

Received: 4 May 2010
Revised: 7 December 2010
Accepted: 20 May 2011
Published online: 18 August 2011

Abstract

An atmospheric pressure plasma source supplied by an electrical circuit consisting of two voltage sources in parallel connection is reported. One of them is a low-power self-oscillating flyback converter which produces negative voltage pulses with an amplitude of several kilovolts. The high voltage pulses are necessary to ignite an electrical discharge between the electrodes at atmospheric pressure. An additional dc source delivering several hundreds of volts at a few hundred milliamps is used to sustain the electrical discharge. The circuit configuration allows the control of the discharge current over a wide range, in a simple manner. By using argon as a working gas, a stable plasma plume up to 8 mm long can be obtained either in a transferred or non-transferred arc mode.