碩士生: 孫宜平
畢業年分: 2018年2月
論文名稱: 立方衛星之微型脈衝電漿推進器之發展 (中文) / Development of micro-scale pulsed plamsa thruster for Cube satellite
英文摘要:
Pulsed Plasma Thruster (PPT) is a form of electric propulsion device in which the plasma is accelerated by the interaction between pulse currents and magnetic fields to create thrust. It is one of the most promising electric propulsion device and were the first form to flown to space on two soviet probes Zond 2 and Zond 3 in 1964. As it is low cost, simple in design, light weight and consumes less total power, it has great advantage in altitude control and station keeping for small satellites. Two different thruster prototypes have been developed. One is solid fed pulsed plasma thruster and the other one is gas initiated pulsed plasma thruster. Solid fed pulsed plasma thruster is very simple and most commonly used thruster in which Teflon is used as propellant and spark plug is used to initiate the discharge, the thruster was tested in high vacuum condition (8×10-5torr) with different gaps and the results showed that the impulse bit increased with the increase in electrode gap. It was also tested with different energies and rise in impulse bit with the increase in energy was observed, the maximum impulse bit seen is 256.98μN-sec at 25J for 15mm electrode gap. Triple Langmuir probe was used to estimate the electron density in the plasma that was accelerated out of the Thruster. The test showed the electron density at 3mm away from the nozzle was 8×1020 m^-3 when the stored energy was 6.25J and electrode gap is 25mm. In Gas initiated pulsed plasma thruster, capacitor gets discharged by ionizing gas between electrodes, argon was used as both propellant and initiator for discharge. The thruster was tested in high vacuum (1.6×10^-4torr) condition with different flow rates from 1sccm to 9sccm and a gap distance of 1mm and 3mm. The discharge was successful at all flow rates and the maximum impulse bit achieved was 1.59μN-sec.
