Publication Date:
2016-01-06
Description:
Anode double layer and droplet shaped fireball are found in a magnetically constricted anode. The disc shaped anode is constricted using permanent magnets. The device has only one anode and vacuum chamber acts as cathode. Plasma is created through glow discharge by applying high voltage between the anode and the cathode. Large size droplet shaped glow is obtained near the anode and is shown to have a double layer structure. Discharge is operated in pressure range from 5 × 10 − 3 mbar to 5 × 10 − 2 mbar keeping discharge current between 1 and 10 mA . Typical plasma density obtained near anode is 1 × 10 10 cm − 3 . The profile of plasma potential clearly shows two distinct regions with potential difference of 15.6 V at the boundary of anode glow. The potential difference is close to the ionization potential of Argon gas, which is used during the experiment. This distinct region is visible as bright anode glow and dark “bulk plasma” fill the chamber. This indicates the presence of the double layer formation. The role of magnetic field is also discussed in the formation of the glow, its shape, and the plasma potential profile.
Print ISSN:
1070-664X
Electronic ISSN:
1089-7674
Topics:
Physics