Plasma Properties of a Low-Pressure Hollow Cathode DC Discharge

Muayad Abdullah Ahmed; Qais Thanon  Algwari; Marwan Hafeedh  Younus

doi:10.24996/ijs.2022.63.6.20

Authors

Muayad Abdullah Ahmed Physics Department, College of Education for Pure Science, University of Mosul, Mosul, Iraq https://orcid.org/0000-0003-3245-3066
Qais Thanon Algwari Department of Electronics, College of Electronic Engineering, Ninevah University, Mosul, Iraq https://orcid.org/0000-0002-6524-946X
Marwan Hafeedh Younus Physics Department, College of Education for Pure Science, University of Mosul, Mosul, Iraq https://orcid.org/0000-0003-1970-8861

DOI:

https://doi.org/10.24996/ijs.2022.63.6.20

Keywords:

Hollow cathode discharge, Langmuir probe, electron temperature

Abstract

The current study involves an experimental investigation of plasma main parameters of a DC discharge with a hollow cathode (HCD) geometry in air using apertures of different diameters from the hollow cathode (1, 1.5, 2, and 2.5 cm). A tiny Langmuir probe is used to investigate the plasma properties. The HCD was operated at constant power of 12.4 W and gas pressures ranging between 0.1 to 0.8 torr. It was observed that the operational conditions strongly affect the electron temperature and density, while the hollow cathode diameter has not much influence. The main important observation was that at relatively high air pressure (>0.4 torr) two electron temperatures were obtained, while at relatively low pressure (<0.4 torr), a single electron temperature was found. The results showed that the measured electron temperature decreased nearly linearly with increasing gas pressure.