Numerical study on heating gas in atmospheric pressure helium discharge

Summary form only given. It has been shown that gas discharge plasmas can have a number of effects on biological objects¹. Today, much attention is paid to the development of gas discharge devices for plasma treatment of living materials. However, production of efficient plasma sources for bactericidal treatment of living tissue must meet the strong requirements for safety and stability of plasma flow parameters. The most important among them which must be controlled are gas temperature, discharge current and plasma composition.The current paper is devoted to numerical study on gas heating in plasma flow of high-voltage DC-discharge in helium at atmospheric pressure depending on electrodes spacing, supply voltage and corresponding discharge current. Computer modeling has been carried out with Comsol Multiphysics. Two-dimensional problem on gas heating in high-voltage atmospheric pressure discharge initiated in nonuniform electric field has been solved. To obtain the data on gas temperature, the steady state of corona discharge plasma has been modeled and its parameters (charged and neutral particle flux densities, electron temperature and others) have been calculated using drift-diffusion approximation2. The initial and boundary conditions have been set according to the following points: - the high-voltage electrode has been made in the form of metal rod with a diameter of 0.5-5 mm; - the second, grounded, electrode in the form of plate is placed from the first one at a distance varying from several millimeters up to values that do not influence on the value and pattern of electrical field; - the high-voltage electrode is supplied with direct negative voltage - 103 V; - the initial spatial distribution of the electron concentration in helium corresponds to Gaussian function. The spatial distribution of gas temperature in the discharge area has been calculated. The range of supply voltage for the discharge with gas temperature that is close to the tempera- ure of ambient air has been revealed. The data on corresponding voltage and current discharge have been obtained.