PIC-MCC Modeling of the Cylindrical Magnetron Discharge

Abstract

Plasma of the DC discharge in cylindrical magnetron is studied on the basis of 1‐D particle‐in‐cell simulation. In 1‐D model the radial dependence of plasma parameters is calculated. The main features of the model are described and the obtained results discussed. The electron particle densities, electric field, and the radial course of plasma potential obtained by model are compared with experimental results. Measurements and calculations have been performed in dc discharge in Ar at the pressures in the range p=1+6 Pa, magnetic fields B=10+40 mT and discharge currents ID=100+400 mA. Presented are results at p=3 Pa and B=10 mT. This model study concerns the novel experimental system constructed in Greifswald University and described e.g. in [1]. In this new system the length of the discharge vessel is 300 mm, radii of inner cathode and outer anode are 9 mm and 29 mm respectively. The axially segmented cathode and axially movable Langmuir probe were implemented. We present comparison of experimental results of radial profiles of electron density, plasma potential, and from it derived electric field, in the discharge plasma with the results obtained from the numerical model. While for the electron density a reasonable agreement is obtained the calculated electric field in the positive column is higher than that obtained from experiment. On the contrary the computed discharge voltage is lower that that observed experimentally.