Variation of High and Low Energetic Electron Densities Across a Magnetic Filter in a Hot Cathode Discharge

In hot cathode discharges, at a pressure (equal to or more than) 10–4 mbar, two electron temperature groups are found to exist. In our experiment, a magnetic filter acts as an electron cooler which divides the whole chamber into two regions: Source and Target. Plasma produced in the source region diffuses towards the target region. The density of high energetic and low energetic electron groups is calculated at different experimental parameters, and a comparative study has been carried out. By changing the plasma production conditions, the density of high energetic electrons and low energetic electrons is observed in the target side. In spite of the use of the magnetic filter, high energetic electrons were still found in the target region, though their density is lower than that of the low energetic electrons. With an increase of working pressure, the density of both high and low energetic electron groups decreased, but as the filament current is increased, there is a significant increase in the density of the two electron groups. On the other hand, with increase in discharge voltage, the density of low energetic electrons increases while the density of high energetic electrons decreases slightly.