## Abstract

Electrons produced in atmospheric pressure corona discharges are used for a variety of beneficial purposes including the destruction of gaseous contaminants, and surface treatment. In other applications, such as electrostatic precipitators and photocopiers, unintended reactions such as ozone production and deposition of silicon dioxide are detrimental. In both situations, a kinetic description of the electron distribution in the corona plasma is required to quantify the chemical processes. In this paper, the electron density and energy distributions are numerically determined for a positive dc corona discharge along a wire. The electron density distribution is obtained from the 1-D charge carrier continuity equations and Maxwell's equation. The non-Maxwellian electron kinetic energy distribution is determined from the Boltzmann equation. The effects of wire size (10-1000 μm and current density (0.1-100 μA/cm of wire) on number density and energy distribution of electrons are presented. With increasing current, the electron density increases, but the thickness of the plasma and the electron energy distribution are not affected. Smaller electrodes produce thinner plasmas and fewer, but more energetic electrons, than larger wires. The effect of electrode size on the electron-impact chemical reaction rate is illustrated by the rates of dissociation and ionization of oxygen and nitrogen.

Original language | English (US) |
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Article number | 363758 |

Pages (from-to) | 199-224 |

Number of pages | 26 |

Journal | Plasma Chemistry and Plasma Processing |

Volume | 22 |

Issue number | 2 |

DOIs | |

State | Published - 2002 |

### Bibliographical note

Funding Information:We gratefully acknowledge the helpful comments and assistance of Dr. Uwe Kortshagen, whose numerical scheme was used to compute the electron energy, and anonymous reviewers whose comments and suggestions were incorported into the final manuscript. The Supercomputing Institute at the University of Minnesota gave financial support in the form of computational time.

## Keywords

- Boltzmann equation
- Corona discharge
- Electron density distribution
- Electron energy distribution