전산모사를 통한 생의학 응용 저온 대기압 플라즈마의 특성 연구

Abstract

Interest in the biomedical applications of low temperature atmospheric pressure plasmas (LTAPPs) has increased tremendously. As the measurements of properties of LTAPPs are not easy, the role of modeling and simulation of LTAPPs has become important in understanding the effects of various operating conditions on charged particles and radicals having biomedical applications. The complex plasma models, such as particle-in-cell Monte Carlo collision and fluid models, are not capable of treating hundreds of reactions and species present in atmospheric air plasmas. However, zero-dimensional global model which is the simplest plasma model can be used for simulation of LTAPPs. Global model is capable of taking hundreds of species and reactions into account. Global model based upon object-oriented method (GMoo) has been developed in this thesis. It has a great advantage over the old global model written in procedure-oriented language

that is expandable. Thanks to the features of object-oriented language, such as encapsulation and modularity, GMoo can add hundreds of reactions and species quite easily.Determination of concentration and rate, of production of reactive and ground state species, such as O, OH, NO, O3 and O2-, in LTAPPs under certain operating condition is one of the main concern of plasma modeling researches. This is because cellular response to different types of species depend on their concentrations. GMoo can provide us with information such as the density of all the species involved in the model, information about generation and loss mechanisms for all the species and electron temperature.GMoo is also used to study argon plasma operated in humid atmosphere. It is founded that LTAPPs with small amount of H2O2 produces five times higher density of OH radical. However the amount of OH production decreases when the amount of H2O2 is higher than 0.6% of Ar. This reduction in amount of OH radical is due to increase of loss owing to collision between OH and H2O2.