Paper Title
Effect of hollow Anode Depthon some Characteristics and Parameters of Argon Glow Discharge Plasma
Abstract
An experimental investigation of hollow anodeargon glow discharge plasma has been carried out at different
argon gas pressure ranged from 2.2 × 10to 3mbar forconstant discharge current. The glow discharge usually obtained by
applying a high voltage between the electrodes sufficient to occurring breakdown of argon gas and sustaining the
discharge.The experiments were conducted firstly to measure the breakdown voltage and Paschenc's law under the influence
of hollowanode depth.A constant cathode disc of radius 20mm as well as hollow anodes of constant inner diameter 20mm
and depths of values (10, 15, 20, 25, 30, 35, and 40) mm have been taken into consideration.Secondly, the study has been
extended to measure some plasma parameters in the negative glow region ofdirect current argon glow discharge under the
same conditions. Electric probes and a computer MATLAB program are used to obtain the temperature and density of
electrons in the negative glow region from the double probes (Ip-Vp) characteristic. It was found from the results that the
measured Pashence's curve closes to the well-known theoretical Pashence's law. The voltage breakdown and its minimum
breakdown voltage decrease due to increasing the depthof cylindrical hollow. Increasing the hollow anode depth, the
Paschen’s curve is widening.A dens and luminous intensity of plasma occurs in the negative glow region due to reduction of
hollow anode depth. Both electron temperature and density of electron are decreases due to increasing the depth.
Keywords- hollowanode depth, argon glow discharge, double probes Plasmaparameters, negativeglow Region,
MATLABprogram.