Expriment And Optimization Of Micro Cathode Arc Thruster

The rapid development of cube star and the demand for task diversification put forward new demands for micro propulsion.The micro cathode arc thruster uses solid propellants to generate transient high voltage of up to hundreds of volts at both ends of the thruster through power processing unit(PPU).Under the action of conductive film,the micro cathode arc thruster can generate electric arc,ionize and accelerate cathode working medium.It has the characteristics of high specific impulse and low power,and does not need to use storage tank.Its mass and volume are small,so it is suitable for completing orbit as a cubic satellite propulsion system Space missions,such as maintenance and formation flying,have good prospects for development.Firstly,this paper introduces the design and experimental conditions of the micro cathode arc thruster,as well as the working principle of the plasma parameter measuring device of the thruster,designs and processes the thruster prototype with simple structure and high reliability.At the same time,the measurement device of ion velocity based on TOF method,the measurement device of ion current based on probe and the measurement device of cathode spot rotation speed based on CCD high-speed camera are designed.In addition,the vacuum environment and equipment of the test are introduced.The test conditions are available,which provides a guarantee for the optimization of the thruster in the next step.Secondly,the optimization of thruster design parameters is studied.The design parameters that affect thruster performance mainly include magnetic field environment,discharge distance between cathode and anode,anode material,and conductive film.The influence rule of thruster parameters under different discharge distance is tested.When brass material with ablation characteristics is used as anode,thrust Finally,the preparation process of the conductive film is studied,and how to spray the conductive film can be more uniform and meet the resistance value when the thruster works,so as to improve the stability of the thruster.Thirdly,study the coupling discharge of PPU and thruster,explore the advantages and disadvantages of the new capacitor circuit compared with the traditional inductance circuit,respectively test the parameters of PPU,including the discharge frequency,input voltage,inductance and capacitance,and the influence of the duty cycle of PPU on the performance of thruster parameters during the coupling discharge with thruster,and explore how to adjust the parameters of PPU to cope with them The working mode of thruster with different working requirements.Finally,the methods of improving the performance of the micro cathode arc thruster are explored,and the array thruster,the multi ring thruster and the magnetic focusing thruster are proposed and designed.Among them,the array thruster and the multi ring thruster can greatly improve the working life of the thruster,and there are many working modes to adapt to different task requirements.The magnetic focusing thruster can restrain the plume and accelerate the axial velocity of the ion by the way of external electromagnetic field.