Effect of voltage pulse duration on electrophysical and thermal characteristics of cold atmospheric plasma jet

The desirable properties of a cold atmospheric plasma jet (CAPJ) for medical applications are high efficiency of the treatment and low thermal effects. To meet these requirements, we propose to use the CAPJ generated with the positive pulsed (PP) voltage. In our experiments and fluid model simulations, it is shown that a change of the pulse duration allows us to control precisely the intensity of interaction of the plasma jet with the target and the heating of the contact zone. The helium CAPJ is formed with 13-30 kHz PP voltage frequencies with the pulse duration of 7-20 mu s. The enhancement of plasma-target interaction is analyzed with the measured discharge current and calculated ionization rate near the target surface. The temperature measurements in the plasma-target active zone show that the heating by CAPJ excited with the PP voltage is generally less than in the case of AC voltage. The efficacy of treatment is tested on A549 cancer cells exposed to CAPJ ignited with the positively pulsed voltage with different pulse duration and with AC voltage.

Automated summary

This study proposes the use of a cold atmospheric plasma jet (CAPJ) generated with positive pulsed (PP) voltage for medical applications. By changing the pulse duration, the intensity of plasma-target interaction and heating in the contact zone can be precisely controlled. The experiments show that the CAPJ excited with PP voltage has lower heating compared to AC voltage. The efficacy of treatment is validated through testing on cancer cells.