Operating characteristics of a high pressure "wire" hollow cathode plasmas

Summary form only given. In this work, a "wire" hollow cathode device was designed using the "pd" constraints, where p is the pressure, d is the gap distance between the electrodes, and was operated in a wide pressure range from 10 mbar to several 100s of mbar. The plasma is generated in this device by a set of thin tungsten wires forming the hollow cathode geometry. The design allows to generate plasma between the individual wires at high pressures, and in the volume enclosed by the wires at lower pressures. The two anodes are located axially at the end of the dielectric cylindrical disk holding the cathode electrodes. The enclosure of the electrode assembly is a cylindrical quartz tube allowing the transmission of the UV radiation from the device. The two end-windows are used for optical diagnosis to investigate the radial distribution of the species by radial mapping of the excitation region in the device.