LOW POWER HALL THRUSTER ST-22 WITH PERMANENT MAGNETS

Abstract

The results of the design, development and testing of the laboratory model of the Hall Thruster ST- 22 are presented. The main attention in the development of the thruster was focused on the optimization of the magnetic field in the accelerating channel of the thruster. When choosing a constructive thruster diagram, it was proposed to use constant magnets and a non -magnetic ring in a magnetic system. The proposed constructive features of the thruster made it possible to exclude a magnetic screen from its design, which led to the simplification of the structure and reduce its mass. Laboratory tests of the ST-22 thruster were carried out when changing the discharge voltage in the range of 160-260 V, as well as with three different values of the mass flow rate of Xenon submitted to the anode - 0.4, 0.5, 0.6 mg/s. In the course of laboratory investigation of the ST-22 Hall thruster, the following characteristics were determined: current-voltage characteristics of the discharge in the acceleration channel of the thruster; the dependences of thrust and specific impulse on the mass flow rate of the working substance and the discharge voltage, as well as the value of the efficiency of the anode block of the thruster on the discharge voltage. As a result of laboratory tests, it was shown that at input power of 100 W, the discharge voltage 215 V and the working substance flow through the anode unit 0.6 mg/s, the thruster provides the thrust value of 7 mN, the discharge current of 0.47 A, a specific impulse of 950 s, and efficiency 33%. The values of the specific impulse and the thruster efficiency were given taking into account the mass flow rate of the working substance in the cathode-compensator. The thruster provides sustainable operation in the range of power consumption of 50 - 100 W and it was designed to use small spacecraft on board, which on board have appropriate electric power.