Structural Optimization And Performance Measurement Of Electron Cyclotron Resonance Plasma Thruster

Electron Cyclotron Resonance Plasma Thruster?ECRPT?is an electromagnetic thruster based on microwave plasma and magnetic nozzle acceleration.The working principle is mainly that the microwave energy is transmitted to the excitation antenna,and then an electromagnetic field is formed on the surface of the antenna,and the free electrons in the working gas make a cyclotron motion under the action of the magnetic field.When the frequency of the electron cyclotron is equal to the own frequency of the microwave,The electrons absorb microwave energy rapidly and become energetic electrons,and the high-energy electrons continuously collide with the working gas to generate a high-density plasma.Finally,the ions in the plasma are accelerated by the magnetic nozzle to generate thrust.The thruster has the characteristics of easy start-up,long life,simple structure,no pollution and stable performance.Because it does not require a neutralizer,the plume is quasi-neutral,it has unique application prospects in deep space exploration,attitude maintenance and orbit control of micro-and nano-satellites in the future.This paper briefly introduces the basic structure of the thruster and analyzes the characteristic structural dimensions of the key components.The HFSS electromagnetic field simulation software is used to simulate the thrust energy microwave energy feeding mode and the antenna structure size.It is concluded that the microwave energy can be utilized more efficiently in the vertical feeding mode.It is 20mm and has a diameter of 0.5mm.By simulating the electromagnetic field distribution on the surface of the antenna,the electric field strength can reach the order of 10³-10⁴,which satisfies the requirements of the electric field required to excite the working gas.The discharge effect and magnetic field configuration of the thruster discharge chamber were simulated by COMSOL multiphysics.The drift diffusion model is used to calculate that the electron density in the discharge chamber can reach the order of 10¹⁸m^-3.Through the structural design,the inner diameter of the thruster discharge chamber is2.8cm,the outer diameter is 3cm,the height is 2.5cm,the inner diameter of the magnet is 3cm,the outer diameter is 5cm,and the height is 2.5cm.Under the condition of determining the material and size of the permanent magnet,the two-dimensional axisymmetric model of the magnet is established,and the magnetic field configuration is simulated.The ECR surface is located at the tail of the thruster,which verifies the rationality of the magnetic field design.In this paper,the experimental prototype of the thruster is designed and processed by the simulation results.The discharge effect of the thruster was verified by the self-built experimental platform,and the characteristic parameters of the thruster plume were diagnosed.The discharge experimental working gas was argon,and it could work stably under the background pressure of 10-2Pa.The Faraday probe was used to diagnose the ion current and ion current density in the plume region under different microwave power and gas flow conditions,which further verified the rationality of the experimental prototype design.