R&D experimental study

Glow dischargecharacteristics with He and H2 have been experimental studied, and also downwith the influence on glow discharging because the clearance between electrodeand its surrounding shielding. For He, if gas pressure ﹥2 Pa , hollow cathodealways can be found in various ports and pipes that without shielding. For H2,hollow cathode can be found if the gas pressure ﹥3 Pa