Abstract
The dielectric barrier discharge (DBD) is one of the most widely used sources for generating non-equilibrium plasmas in atmospheric pressure. Especially, plate-type DBD reactors filled with helium gas have been intensively investigated because they easily produce homogeneous glow plasmas, which are useful for their industrial applications to materials and environmental processing. In practical applications of atmospheric glow plasmas to surface treatments and hazardous gas decompositions, chemically active species including oxygen atom and molecule in the plasma play an important role. However, oxygen adversely affects the stability of glow plasma due to quenching electrons. Thus it is essential to know the quantities of oxygen impurities in the helium plasma for compromising their two conflicting effects of radicals generation and destabilizing operation in the dielectric barrier glow discharge (DBGD). In this numerical work, a one-dimensional numerical model of the dielectric barrier discharge in a glow mode has been developed for the non-equilibrium helium plasma in atmospheric pressure to resolve the above-mentioned problem. A set of continuity equations of charged particles including electrons, positive ions and metastably-excited species are considered, and an RCIP (Rational Cubic Interpolated Propagation) scheme is employed to solve the equations accurately and minimize the numerical diffusions in their solutions. Poisson's equation coupled with the continuity equations is used for the calculation of electric field. In addition, the electron transport and interaction parameters are calculated from integrals of the electron energy distribution functions (EEDF), which are obtained by using a time-dependent Boltzmann equation solver. A typical one-peak shape of current is appeared in the DBGD operated with an audio-frequency range of applied voltages, and the spatial distributions of density and electric field are plotted which are similar to those obtainable in the low pressure glow discharge. Then, the dependence of plasma stability on the amount of oxygen impurities is discussed on the basis of calculated results.
Original language | English |
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Pages (from-to) | 159 |
Number of pages | 1 |
Journal | IEEE International Conference on Plasma Science |
State | Published - 2003 |
Externally published | Yes |
Event | 2003 IEEE International Conference on Plasma Science - Jeju, Korea, Republic of Duration: Jun 2 2003 → Jun 5 2003 |