Plasma discharge characteristics of wall segmentation with high biased electrode in Hall thruster
2018, 38 (5):
Hall thruster plasma has strong interactions with the channel wall. In order to reduce the surface corrosion and enhance the lifetime, a twodimensional physical model was established based on the discharge process of Hall thruster, and a Particleincell (PIC) simulation method was applied to study the influences of segmented low emissive graphite electrodes on discharge characteristics of the Hall thruster channel. The influences of biased segmented electrode arranged in the ionization region on electric potential, ion number density, electron temperature, ionization rate, discharge current and impulse were discussed. The results show that segmentation of high biased electrodes at different positions in the ionization region has obvious influences on the plasma discharge characteristics. When the electrode position is in the front ionization region and the electrode bias voltage is 60V higher than the anode, the plasma parameters of discharge channel are almost unchanged. When the electrode is at the end of the ionization region, and the electrode bias voltage is 18V higher than the anode, the accelerating region expands axially, the ion velocity vectors are more focused, the electron temperature increases significantly which decreases the interaction between electrons and wall, and the divergence angle of the plume also reduces. The thruster specific impulse increases about 12%, the performance and lifetime of the thruster are improved.
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