Starting Modes of Bi-Directional Plasma Thruster Utilizing Krypton

Abstract

Multidirectional plasma thrusters are of particular interest for dynamic space missions due to the adjustability of their integral characteristics. One type of multidirectional plasma thrusters is -directional, consisting of a symmetric electromagnetic system surrounding the gas discharge chamber, capable of generating a propulsion minimum in two directions. The experimental results of this study of the starting modes of a multidirectional plasma thruster utilizing krypton as propellant are reported. The thruster is placed in a vacuum chamber. The magnetic field strength is adjusted in the range of 35 to 400 G in peaks. The current of 13.56 MHz frequency applied to the antenna is regulated in the range of 0 to 25 A. The diameter of the orifices is varied in the range of 3 to 10 mm. In contrast to the unidirectional electrodeless plasma thruster, the radiofrequency breakdown threshold of the multidirectional plasma thruster decreases with increasing static magnetic field due to the symmetry of the magnetic system and the gas discharge chamber. The influence of the magnetic field on the radiofrequency breakdown threshold in the multidirectional plasma thruster is shown theoretically by the classical diffusion theory and ponderomotive effects, and discussed in the electron circulation hypothesis.