Characteristics of abnormal glow discharges

Here we report the work done in the case of abnormal glow discharge in air at low pressures. The breakdown voltage measurements and I-V characteristics are obtained to find the region and the partial discharge (PD) conditions corresponding to abnormal glow discharge which also tries to occupy the maximum possible volume of the chamber. The charge density, electron and ion temperature and floating potential measurements are carried out using a Langmuir probe along with breakdown current pulses for understanding different regions of glow discharges. The floating potential measurements show fluctuations upto the 7% level near the anode and the level decreases as one goes away from the anode in a positive column of the discharge. These fluctuations are related to the ion acoustic oscillations in the positive glow region. We could obtain the maximum charge density of 10¹³ cm^-3 with ion temperature in the range of 7-9 eV. It is expected that these results can help in understanding the behavior of abnormal glow discharge which shows different characteristics under different experimental conditions and has various applications