Glow-like atmospheric pressure micro-discharges produced by charge rollers

Abstract

Summary form only given. Conductive charge rollers (CR) are used in print engines for surface charging of the cylindrical photoconductor (PC) at atmospheric pressure. The charging process is essentially a dielectric-barrier-discharge (DBD). Microplasmas are produced in the narrowing gap between the CR and PC, which then charges the PC. The streamer-like plasmas can be terminated by surface charging of the PC if operated with a dc or quasi-dc voltage on the CR. From a practical matter, the surfaces of both the CR and PC are rotating. The rotation of the PC brings in uncharged surface which reestablishes the voltage between the CR and PC, and re-ignites the plasma. As a result, a periodic charging pattern on the PC surface may be formed. Under certain operating conditions, a glow-like discharge was simulated in the CR and a quasi-dc current was collected on the PC surface. These behaviors and the uniformity of surface charging are sensitive to the speed of the PC and applied voltage.In this presentation, we will discuss the behavior of atmospheric pressure microplasmas sustained in air between the CR and PC, and the charging properties on the PC surface using results from a 2-dimensional simulation. The model, nonPDPSIM, solves Poisson's equation and transport equations for charge and neutral species and the electron energy conservation equation for electron temperature. A Monte Carlo simulation is used for tracking sheath accelerated electrons. Rate and transport coefficients for bulk electrons are obtained from local solutions of Boltzmann's equation for the electron energy distribution. Radiation transport is addressed using a Green's function approach.