无热子空心阴极点火电压的温度敏感性研究

Previous studies on the startup characteristics of heaterless hollow cathodes（HHC）primarily focuses on ambient and elevated temperatures. However，considering the typical temperature range （-65 to 125 ℃）in near-Earth orbit space applications，it is essential to investigate HHC startup characteristics under low-temperature conditions to analyze their temperature sensitivity. This study established an HHC design and radiative thermal control experimental system. Using vacuum environment simulation equipment，the ignition current and voltage parameters of HHC at different initial temperatures were measured，and the variation patterns of the ignition voltage of HHC with initial temperature were analyzed. Experimental results demonstrate that：（1）The ignition voltage curves under various initial temperatures qualitatively conform to Paschen’s law；（2）Temperature variations induce systematic shifts in ignition voltage curves-low temperatures cause leftward shifts toward characteristic values while high temperatures induce rightward shifts；（3）The ignition voltage curve exhibits steeper slopes under low temperatures and flattens at high temperatures；（4）The minimum ignition voltage remains essentially constant across different temperatures. Theoretical analysis reveals that this shifting phenomenon primarily stems from temperature-induced alterations in the mean free path of inelastic collisions between electrons and neutral particles，leading to parameter value changes in Paschen’s law. A temperature coefficient is proposed to refine the theoretical model，enabling the ignition voltage requirements at target temperatures to be effectively predicted.