Physical characteristics of a stable un-magnetized Discharge Medium

Proper design of plasma cell based on a low pressure cold-cathode discharge has been constructed, in our laboratory. The cell has been confined in unmagnetized chamber and was limited to operate in the glow discharge region. Glow discharges operated in such cell that was filled with different working gases; argon, nitrogen, or oxygen, explored abnormal current-voltage characteristics at discharge current of several m A. A substantial interest is devoted to study the physical characteristics of these discharge media. Hence, the effect of argon gas pressure on both the discharge voltage and the discharge current at a gap distance d=2 cm, was investigated. Then, the work was concentrated on the results of the electrical breakdown measurements in these discharge media. The measurements were taken at different pressures, P, and fixed inter-electrodes gap distance, d. The influence of the cathode material (aluminum, copper or stainless steel) on the electrical breakdown measurements was investigated, as well. The secondary electrons released from the cathode play a dominant role in the initiation of the electrical breakdown. The secondary electrons were created by the charged particles bombardments and the neutral species, as well