Abstract
Electrical measurements are an important tool for the characterisation of glow discharges and have proved to be useful for a variety of needs in fundamental studies and as control parameter. Therefore, extensive hardware developments and studies of current-voltage (I-U) characteristics in continuous and pulsed, dc and rf modes have been made [1] and will be presented together with new results.
In continuous dc mode, the I-U curves are non-linear and may be characterised by a threshold voltage U0 and saturation current Imax (both cathode material and pressure dependent). On the other hand P-U curves are to a large extent linear and very similar in the continuous rf mode [2]. The ionic part of time resolved I-U curves of rf discharges however shows almost a linear behaviour and the capacitive component is small. This led to the assumption that gas heating is responsible for the non-linearity between I and U in continuous dc discharges. Consistent with this assumption, a dependence of the I-U curves of pulsed discharges on the duty cycle was found. The comparison of the curves with those at low duty cycle (cold) led to a rough estimation of the gas temperature.
Further investigation and cooperation with modelling groups is needed and planned to explain these results.
Export citation and abstract BibTeX RIS