In order to improve the uniformity of the neutral atom distribution in the discharge channel of the low-power Hall thruster, the finite element method was used to optimize the key structural parameters of the anode gas distribution ring. Aiming at the double-chamber anode gas distribution ring structure, the influence of key parameters such as the volume ratio of the buffer chambers and the number of diversion holes between the buffer chamber partitions on the uniformity of anode gas supply was analyzed. The research results show that with the increase of the volume ratio, the difference of the anode gas distribution ring outlet pores decreases rapidly and then stabilizes. When the ratio k=1.0, the average difference rate and the maximum difference rate are 1.77% and 3.79%, respectively; when the number of diversion holes between the buffer chamber partitions increases from 8 to 14, the difference rate of the air outlets shows the characteristics of the bathtub curve, and when number of the diversion holes is 10, the average difference rate and the maximum difference rate are 1.8% and 3.8%, respectively. The research results can provide theoretical support for the engineering design of the anode gas distribution ring of the Hall thruster.

The beam properties of the micro Hall thruster µHT-1, which is intended for space gravitational wave detection, are being experimentally investigated for the first time. A Faraday probe combined with a three-dimensional mobile mechanism was used for diagnosis, and the beam ion current density distribution under a wide range of the anode voltage from 700 to 1200 V and the anode mass flow from 0.1 to 0.5 sccm was obtained. Moreover, the variation trend of total ion beam current, anode current, current utilization efficiency, beam divergence angle and other parameters were further analyzed. According to test data, the spatial distribution of beam ions changes from dense to sparse as one moves away from the axial direction of the µHT-1 thruster. Additionally, the beam becomes more flat due to the diffusion motion of beam ions in space and the binding motion of electrons and ions. The µHT-1 thruster can work stably under a wide range of conditions (anode voltage 700～1200 V, anode mass flow 0.1～0.5 sccm), and the beam current presents a good axis-symmetric distribution. With the increase of anode voltage, the average temperature of electrons can be increased, which further leads to the increase of ionization rate, that is, the current utilization efficiency increases from 53.4% to 67.7%; and the magnetic field restraint ability of high-energy electrons is weakened, affecting the electric field focusing, and the beam divergence angle increases from 41.3 ° to 56.1 °. With the increase of anode mass flow, the neutral atom density distribution in the channel is affected, the current utilization efficiency fluctuates in the range of 57.1 % ～ 66.8 %; and the ion collision zone is transferred to the outlet, making the beam divergence angle increase from 43.4 ° to 56.7 °. The total ion beam current of the thruster changes linearly with anode mass flow and anode voltage, which provides the data basis for the subsequent thrust wide range adjustment and thrust resolution analysis.