Experimental and simulation study of pulsed micro-hollow cathode discharge in atmospheric-pressure helium

In this paper, we present an experimental and numerical study on micro-hollow cathode discharge (MHCD) in helium at atmospheric pressure. The discharge in the micro-hollow cathode is driven by a -700 V pulsed power supply with the μs width and kHz frequency. The electrical characteristics were obtained by the experimental measurement and a self-consistent fluid model. The waveforms of the voltage and discharge current obtained by simulation are highly consistent with those obtained by experiments. The electrical characteristics, the spectra, and the distribution of the discharge plasma indicate that an abnormal glow discharge was formed in the MHCD. The spatial-temporal evolutions of the discharge show that the maximum plasma density can attain about 10¹⁵ cm^-3. The averaged plasma density is over 10¹⁴ cm^-3 during the discharge, and the plasma can be maintained for a long time during the afterglow period. The discharge current density can reach 30 A cm^-2. All results show that a strong ionization and excitation can be generated by pulsed micro-hollow cathode discharge which is suitable for chemical analysis.