Design And Experimental Study On The Conceptual Verification Device For Wave-heating Plasma Magnetic Nozzle Thruster

Wave Heating Plasma Magnetic Nozzle Thruster(WHPMNT)has the advantages of high power,high specific impulse and adjustable Thrust/Specific-Impulse at fixed power.It is an important candidate propulsion system for performing deep space exploration missions in the future.Since the concept of WHPMNT was put forward,related progress has been continuously made around the world,which further demonstrates its application prospect.The domestic research at present on WHPMNT is related to the study and design of subsystems such as helicon antenna and magnetic field configuration.Systematic design and modeling,whole construction of the device and ignition test has been accomplished in this paper,which is of importance to the deep understanding on the working principle and further optimizing of the WHPMNT.Multi-physics coupling design and simulation on the magnetic configuration of heating stage and magnetic nozzle has been carried out.The design principle of the magnetic configuration is proposed according to the type of gas and plasma constraint requirement.The systematic coupling analysis including electric,magnetic,hydrodynamic and heat transfer is carried out,especially the heat problem to generate strong magnetic field with constant-conductivity electro-magnetic coils.A reasonable schedule is proposed base on the analysis above.The configuration of the Helicon antenna and ICRH antenna is determined and the impedance matching system is designed respectively.The power-on test shows that the impedance matching system works well,with a reflectivity of 0 for Helicon antenna and11% for ICRH antenna under 100 W input power.A wall-mounted external discharge design scheme is proposed in this paper.The configuration of the discharge chamber is designed based on the requirement of construction of the device and acceleration of the plasma.The material of the chamber is selected according to the need of direct diagnosing on the plasma parameters during hightemperature region with optical method.The mechanical properties simulation is carried out to verify the strength of the chamber.The experimental results show that the external discharge scheme works well.On the basis of design of each main sub-system,the overall construction of the WHPMNT device is completed by appropriate water tube,circuit and gas path.The test on the exciting system of strong magnetic field shows that the system can generate the specific magnetic field and can operate continuously with a temperature increment of around 40℃.The test on the antenna shows that the low-pressure air can be ionized effectively and the reflection coefficient is within 1% for Helicon antenna and 20% for ICRH antenna with 800 W input power.The low-pressure air is ionized and significantly acceleration under the condition of strong magnetic field and the apparent plume can be observed.