Characteristics of a novel nanosecond DBD microplasma reactor for flow applications

TL;DR

This paper introduces a novel nanosecond pulsed dielectric barrier discharge microplasma reactor for flow applications, capable of generating non-thermal plasma at atmospheric and sub-atmospheric pressures with detailed characterization.

Contribution

The study presents a new microplasma reactor design using nanosecond high-voltage pulses, with comprehensive analysis of its electrical, optical, and plasma properties under various pressures and flow conditions.

Findings

Reactor operates continuously up to 100 minutes in air.

Pulse energies of 1.9 μJ at atmospheric pressure and 2.7 μJ at 50 mbar were measured.

Effective electric field strength E/N varies from 500 Td to 2000 Td with pressure changes.

Abstract

We present a novel microplasma flow reactor using a dielectric barrier discharge (DBD) driven by repetitively nanosecond high-voltage pulses. Our DBD-based geometry can generate a non-thermal plasma discharge at atmospheric pressure and below in a regular pattern of micro-channels. This reactor can work continuously up to about 100 minutes in air, depending on pulse repetition rate and operating pressure. We here present the geometry and the main characteristics of the reactor. Pulse energies of 1.9 $\mu$J and 2.7 $\mu$J per channel at atmospheric pressure and 50 mbar, respectively, have been determined by time-resolved measurements of current and voltage. Time-resolved optical emission spectroscopy measurements have been performed to calculate the relative species concentrations and temperatures (vibrational and rotational) of the discharge. Effects of the operating pressure and the flow velocity on the discharge intensity have been investigated. In addition, the effective reduced electric field strength E/N has been obtained from the intensity ratio of vibronic emission bands of molecular nitrogen at different operating pressures. The derived effective E/N increases gradually from 500 Td to 600 Td when decreasing the pressure from one bar to 0.4 bar. Below 0.4 bar, further pressure reduction results in a significant increase in the effective E/N up to about 2000 Td at 50 mbar.