A study of discharge fluctuations in magnetically-supported do discharge in cylindrical and inverted cylindrical configuration

We have investigated apparently stochastic fluctuations of magnetically-supported do discharge in cylindrical configuration. In our system the electric field had radial direction while the magnetic field was applied axially. The discharge vessel length was 12 cm. In the conventional arrangement the water-cooled cathode is positioned at the system axis, connected to the negative pole of the power supply and the grounded surrounding cylindrical vacuum vessel serves as anode. In the inverted configuration the polarity is swapped, i.e. the electrode at the system axis is positive with reference to the cylindrical vacuum vessel, which remains grounded. Advantage of the inverted configuration is much bigger cathode surface area and hence possibility to reach higher powers deposited in the discharge. The contribution describes experimental results obtained using both conventional and inverted magnetron configuration and compares them to recent literature results. Working gas was argon (purity 5.6) at pressure of several Pa, magnetic field 20 divided by 40 mT.