Analysis of Effect of Ground Experiment Environment on Plasma Contactor Performance

Abstract

The large difference in the working performance of a hollow cathode plasma contactor between the ground and actual on-orbit environments will cause difficulties in selecting a ground-test schemes to fully simulate the contactor real on-orbit characteristics. In this study, the effect of the simulated anode size and structure, the simulated anode surface state, the flow rate of background working gas, and the background plasma density on the emission characteristics and plume structure of the contactor are studied. Three self-made simulated anodes of different sizes and structures are applied in the ground experiments. The change of anode surface state (particularly the ability of absorbing electrons) is realized by dividing the self-made simulated anodes into four double-separated regions and alternatively electrically isolating them. An additional gas channel and an auxiliary contactor are used to create background working gas and a low-Earth-orbit plasma atmosphere, respectively. The voltage–current curves as well as the plasma parameter distributions at the contactor exit and in the far-field regions are determined under different regimes and working conditions. The relationship between the contactor’s emission characteristics and plume structure is clarified. The experimental results could provide useful information for instructing the contactor design and developing a real on-orbit experiment plan.

Analysis of anode surface roughness influence on heaterless hollow cathode discharge

“…However, these oxide surface layers presented challenges; they could be readily sputtered by ion bombardment, which curtailed their operational lifespan [16]. Therefore, dispenser cathodes were developed to address this issue by continuously replenishing the low work function surface layer [17,18]. This innovation allowed higher emission current densities and extended lifetimes compared to oxide-coated cathodes [19].…”

A pulsed hollow cathode discharge operated in an Ar/N2/O2 gas mixture and the formation of nitric oxide.

“…The discharge is sustained by electrons undergoing a pendulum motion inside the HC [2][3][4][5][6][7]. Hollow cathode discharges are employed in many applications, e.g., in atomic spectroscopy [1, [8][9][10], mass spectrometry [11], and laser technology [12], as UV generators [13,14] and propulsion thrusters [15,16], for the generation of neutral and ion beams [17,18], surface processing [19], thin film deposition [20][21][22][23][24][25][26][27], and in plasma chemical investigations [28][29][30][31][32][33][34].…”