Basic data for atmospheric pressure non-thermal plasma investigations in environmental and biomedical applications

The aim of this paper is to discuss some aspects of the optimization of the active species generated by corona or DBD discharges at atmospheric pressure which are very useful in the field of plasma environmental and biomedical applications. For such an optimization, this paper targets, in particular, the use of discharge modeling tools and the problem of accuracy of the required basic data. First of all, an overview on the different experimental diagnostics used for the characterization of these non-thermal plasmas is given followed by a short description of the different models (streamer dynamics, gas dynamics and chemical kinetics coupled with models of basic data calculation) required for complementing such experimental investigations. Then, emphasis is placed on the basic data of charged particles (electrons and ions) needed for streamer dynamics modeling and particularly on the necessity to use accurate and validated basic data in order to have a quantitative (not only qualitative) description of the phenomena and processes occurring in such discharges. An overview is given on the calculations and the fitting methods of collision cross sections and swarm coefficients of the data of charged particles and their validation using, in particular, pulsed Townsend measurements for experimental comparisons. Swarm coefficients are calculated from a multi-term solution of the Boltzmann equation or from Monte Carlo simulation. Some illustrative results are given in the case of the simulations of a dc positive point-to-plane corona discharge in air at atmospheric pressure. The effect of consideration of some basic data, particularly those of polyatomic ions, is shown on the discharge development and the radical production.