Simulations of biomedical atmospheric-pressure discharges

Abstract

The comparison between fluid and particle-in-cell simulation results in different nonthermal helium plasma sources: including an overview of kinds, strengths and limitations of the numerical models is reported. The kinetic information indicates that the electron energy probability function (EEPF) evolves from a three-temperature distribution in RF atmospheric-pressure discharges into a Druyvesteyn type distribution as the driving frequency increases. In microwave helium microplasma, the power delivered to the electrons in the bulk increases, and as a result, the EEPF becomes closer to a Maxwellian distribution. Although the results obtained with fluid models that a Maxwellian energy distribution function are not capable of capturing nonlocal effects in high pressure discharge, the appropriate fluid models will be a good selection to investigate particular problems because of their short simulation time. In addition, since frequent ion-neutral collisions limit the energy acquired by the ions as they transit the sheath, the average ion energy near the electrodes is found to be significantly lowered at atmospheric pressure. (c) 2009 Elsevier B.V. All rights reserved.