Optical and electrical investigation of DC micro-hollow cathode discharge in He/O2 and He/H2 mixture

A hollow cathode discharge source was developed using a negatively biased micro-hole cathode to generate high density point-like plasma. Through electrical and optical investigations, the properties of gas discharge plasmas such as dissipated power, electronic excitation temperature, and rotational temperature were compared in glow and hollow cathode discharge conditions. In the hollow cathode discharge mode, the power consumption and excitation temperature were larger. It was also observed that the relatively higher intensity of vacuum ultraviolet (VUV) oxygen triple lines in He/O2 plasma and VUV hydrogen Lyman-α line in He/H2 plasma were realized in the hollow cathode discharge mode.A hollow cathode discharge source was developed using a negatively biased micro-hole cathode to generate high density point-like plasma. Through electrical and optical investigations, the properties of gas discharge plasmas such as dissipated power, electronic excitation temperature, and rotational temperature were compared in glow and hollow cathode discharge conditions. In the hollow cathode discharge mode, the power consumption and excitation temperature were larger. It was also observed that the relatively higher intensity of vacuum ultraviolet (VUV) oxygen triple lines in He/O2 plasma and VUV hydrogen Lyman-α line in He/H2 plasma were realized in the hollow cathode discharge mode.