Performance Evaluation of Magnetic Nozzle by Using Thermal Plasma

The development of new propulsion system for exploring the moon and other planets in the solar system or deep space is necessary to achieve short mission term and large payload ratio. In recent years, magnetic nozzle is focused on as the candidate system to attain above objectives. Magnetic nozzle is the system which generates the thrust by converting the thermal energy of the plasma injected in the nozzle magnetic field formed by radial magnetic field into the directed kinetic energy. The objective of the present study is to clarify the performance of the new proposed plasma source which consists of LaB6 cathode. Furthermore, it is also the objective to measure the thrust and evaluate the performance of magnetic nozzle with LaB6 plasma source. The performance evaluation of LaB6 plasma source is conducted by measuring the plasma temperature and density by applying the double probe method. The thrust evaluation is conducted in the vacuum chamber. In the present experiment, we succeeded in measuring the thrust of thermal plasma and magnetic nozzle. As a result, the thrust of thermal plasma is 4.7 mN, and the thrust of magnetic nozzle is 16 mN. Therefore, the thrust of magnetic nozzle is 3.3 times larger than that of thermal plasma. Furthermore, thrust-power-ratio is 8.99 mN/kW, specific impulse is 4437.8 s and propulsive efficiency is 19.5%. Every performance of magnetic nozzle is also improved than those of thermal plasma.