Study of Plasma Hollow Cathode Jet in Cylindrical Shape
Khaled Hussien Metwaly and Y.H. Elbashar
A low pressure pulsed DC hollow cathode plasma jet system has been investigated. The design is developed to have a high density of plasma jet stream for plasma generation application. Experiments were carried out at charge voltage 4KV and argon gas pressure 10-2 torr. The discharge current was measured by Rogoviski coil while the discharge voltage by a resistive potential divider. The results indicated that the current voltage characteristics of hollow cathode discharge was dumping oscillation and was found to have breakdown voltage 1.92 KV, and maximum current 6.7KA, at the argon pressure 10-2 torr. The photograph of light emission from pulsed DC hollow cathode plasma jet showed the expanding discharge with the densest plasma at the outlet of the nozzle. The time evolution of electron density and temperature were presented using I-V characteristic of single electric probe along the central axis of plasma jet system. The electron temperature and the density were around 6.2eV and (7×10-17 m-3 ) to 3.8eV (2.3×10-19 m-3), respectively, near the nozzle. The growth of electron temperature is related to the cathode voltage, and the electron temperature decreases at the end of the pulse time. The density variations is synchronized with the discharge current because of the Lorentz force.
Keywords: Plasma physics, hollow cathode plasma jet, high voltage physics, copper sputtered