Milos Tichy

PIC‐MCC Modeling of the Cylindrical Magnetron Discharge

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...

Experimental Study of Axial Plasma Parameter Variations in the Cylindrical Magnetron Discharge

In the cylindrical magnetron the electric field is applied in radial direction and the magnetic field in axial direction. In this paper we present a study of the variations of plasma parameters in both the axial as well as in radial directions in the novel construction of cylindrical magnetron developed in the University of Greifswald, FRG. Six evenly distributed coils create the axial magnetic field. The homogeneity of the magnetic field ±0.2 % has been achieved over the whole discharge vessel length 300 mm (vessel diameter 58 mm). The system is equipped with three cylindrical Langmuir probes movable in radial direction, placed in ports located in between each couple of coils in distance 60 mm from each other. In order to measure the axial variations of the discharge current, one half of the cathode length is segmented into 14 segments, i.e. one segment has a length of about 10 mm. This enables the measurement of the axial variations of the discharge current. We present measurements of the axial distribu...

Kinetic Modeling Of Axially Non‐Uniform Cylindrical Magnetron Discharge

Cylindrical magnetron discharges (CMD) with two co‐axial electrodes and a uniform magnetic field being directed axially, represent relatively simple systems for theoretical studies that can contribute to better understanding of discharge operation. The dc discharge in Ar at pressure 3 Pa, magnetic field strength 100 G and current 150 mA is considered where the pronounced non‐local regime of the electron distribution function (EDF) formation is realized. The electron component is analyzed on the basis of radially and axially inhomogeneous Boltzmann kinetic equation. Unmagnetized electrons, which move in axial direction are trapped in the axial potential well, their energy relaxation length is large, and the kinetic equation can be averaged over discharge length. Using a model two‐dimensional potential profile, the EDFs at different axial positions are obtained and spatial distributions of the electron density and ionization rate are represented and discussed. The results of the modeling can be used for exp...