Characteristics of a novel nanosecond DBD microplasma reactor for flow applications

摘要

We present a novel microplasma flow reactor using a dielectric barrierdischarge (DBD) driven by repetitively nanosecond high-voltage pulses. OurDBD-based geometry can generate a non-thermal plasma discharge at atmosphericpressure and below in a regular pattern of micro-channels. This reactor canwork continuously up to about 100 minutes in air, depending on pulse repetitionrate and operating pressure. We here present the geometry and the maincharacteristics of the reactor. Pulse energies of 1.9 $\mu$J and 2.7 $\mu$J perchannel at atmospheric pressure and 50 mbar, respectively, have been determinedby time-resolved measurements of current and voltage. Time-resolved opticalemission spectroscopy measurements have been performed to calculate therelative species concentrations and temperatures (vibrational and rotational)of the discharge. Effects of the operating pressure and the flow velocity onthe discharge intensity have been investigated. In addition, the effectivereduced electric field strength E/N has been obtained from the intensity ratioof vibronic emission bands of molecular nitrogen at different operatingpressures. The derived effective E/N increases gradually from 500 Td to 600 Tdwhen decreasing the pressure from one bar to 0.4 bar. Below 0.4 bar, furtherpressure reduction results in a significant increase in the effective E/N up toabout 2000 Td at 50 mbar.