An overview of modelling of low-pressure post-discharge systems used for plasma sterilization

We present the modeling of a low pressure post-discharge system used for plasma sterilization, which consists of a flowing microwave discharge, an early-afterglow region developed downstream of the discharge in the same tube, and a large post-discharge reactor. The kinetic model valid for the discharge and early-afterglow region is based on the Boltzmann and rate balance equations, while in the post-discharge reactor a 3-D hydrodynamic model is used. The calculations are conducted in an N2-O2 mixture, which has seen to constitute an efficient system for sterilization purpose. The possibilities offered by modeling is presented through a discussion of the effects on relevant species densities and distributions caused by varying: (i) the initial gas mixture composition; (ii) the length of early-afterglow zone; (iii) the gas flow rate and gas pressure.