Abstract

We have investigated the plasma properties of a Hollow Cathode Discharge (HCD) using different dimensions of hollow cathode aperture (1 to 8 mm) in argon operating medium. The diagnostic used to investigate the plasma properties is a tiny Langmuir probe. The diameter and length of the Langmuir probe was chosen such that it draws a measurable current from the plasma causing a minimal perturbation to the surrounding plasma and remains rigid within the plasma as well as the cylindrical probe theories are applicable while calculating the electron temperature and plasma density. The probe was placed perpendicular to the axis of the hollow cathode at a distance of 20 mm from the hollow cathode side. The HCD was operated in the voltage range of 600 to 1000 V and pressures range of 70 to 100 mtorr. We observed that electron temperature and density varies with the operational condition. The estimated electron temperature is less than 10 eV and the temperature is maximum in the range of 3 to 5 mm diameter of the hollow cathode and a pressure range of 75 to 85 mTorr. The calculated maximum density is of the order of 1010 cm-3. © 2006 American Institute of Physics.