Research On The Working Principle Of Helicon Plasma Thruster

Helicon wave plasma (HWP) is a kind of magnetized plasma with high density, low temperature and low pressure. Electromagnetic waves usually propagate in the plasma column that is parallel with the static applied magnetic field in whistler wave mode. Specific RF antenna around the outer wall of the quartz tube excites the right hand polarized wave. Under the low pressure condition of 10-'Pa, the ideal plasma density can reach 1017?1019m-3, and the ionization efficiency of the central area can be approximate to 100%. The double layers acceleration effect can make ions accelerate and eject to produce thrust.As a new type of electromagnetic thruster, it is important to study the working principle of helicon plasma thruster (HPT). According to the existing research results and related theories about electric propulsion in the domestic and overseas, this paper analyzed and summarized the ion acceleration technologies, simulated the formation of double layers, calculated the plasma characteristic parameters of discharge chamber, built the electric propulsion vacuum experiment platform, designed the principle prototype of the helicon plasma thruster, and observed the discharge phenomenon finally. The main research contents are as follows:Starting from the limitations of traditional chemical propulsion, this paper introduced the advantages of the advanced aerospace propulsion technologies as well as their respective characteristics. In particular, the prominent advantage and development potential of electric propulsion compared with other propulsion technologies were pointed out, then the characteristics of helicon plasma thruster and the application prospect in the field of electric propulsion were presented.The structure and discharge features of three types of radio frequency plasma sources were analyzed. According to the working principle of helicon plasma thruster, the viewpoint that the plasma obtains energy through landau damping and double layers acceleration effects was summarized. The ion acceleration technologies were summarized and the optimization design ideas were proposed.In the research on the working principle of the helicon plasma thruster, the simulation models with different lengths of ionization areas and diffusion areas were established and calculated using one dimensional PIC/MCC method, resulting in the pressure ranges and loss coefficient ranges in which high density plasma appeared and stable potential drop formed, that means not only the existing rationality of the double layers acceleration effect was proved, but also its influence factors were obtained, providing theoretical support for the further research on the helicon plasma thruster. The whole models of discharge chamber were established and the corresponding parameters were given using COMSOL multi-physics coupling finite element simulation software, simulating the real working state, getting the spatial distributions of electron number density, electron temperature and collision power loss inside the discharge chamber. Based on the current conditions in laboratory, the four kinds of our own designed antennas are used for discharge experiments to observe and compare the experimental phenomena, and the preliminary conclusions are discussed.