Multistage Micro-Cathode Arc Thrusters
Open AccessMulti-stage Micro-cathode arc thruster is a micro-propulsive device developed at MPNL GWU to increase the thrust and thrust-to-power ratio of a fully developed Micro Cathode vacuum Arc Thruster (μCAT). This two-stage propulsion system is based on a micro-cathode vacuum arc thruster with magneto plasma dynamic second stage (μCAT-MPD). A prototype was developed, and superior performance was demonstrated. It generates thrust up to 1.7 mN at a Thrust to Power Ratio (TPR) of 37.4 mN with 50% efficiency. Considering its TPR vs. Specific Impulse (I_sp) trend, this propulsive system would be energetically beneficial and increase the longevity of the CubeSat lifetime. It is also potentially an alternative propulsive device to the existing Hall thrusters because of its lightweight (~100 g) and requires low power (<50W) for its operation.The primary objective of this thesis is to provide insights into the conceptualization development and characterization of μCAT-MPD thruster. It is demonstrated that adding a pulsed MPD stage, referred to as Lorentz force accelerators to μCAT, further increased the ionization and the velocities of quasi-neutral plasma. Thus, several methods characterized the plasma generated before and after adding the acceleration stage, such as the time-of-flight and total-ion-currents methods. Thrust produced by the μCAT-MPD thruster was measured using the thrust stand and compared with the simulated results. The primary results of thrust produced due to the acceleration stage were discussed. The μCAT-MPD thruster was further optimized by decreasing the distance between the first-stage cathode and accelerating stage electrode for continuous arcing. This optimal gap between electrodes increased the thrust. From the results of the optimized model, it is observed that the thrust generated by μCAT-MPD is proportional to JXB. Therefore, experiments were performed by varying the magnetic field, i.e., changing the intensity of the magnetic field and positioning the magnetic field concerning the discharge area. The results were discussed and demonstrated that by controlling the position of the magnet, the thrust can be increased or decreased. Furthermore, new ideas were investigated, and proven that optimizing the shape of the second-stage electrode can increase the thrust. Two different models were developed: multi-segment μCAT-MPD thruster and thin-plated μCAT-MPD thruster. A series of experiments were conducted by increasing the MPD stage electrode from the first stage, increasing the diameter, and decreasing the thickness of the electrode. The initial results demonstrated that the ion velocities, ion currents, and thrust were increased by varying the second-stage electrode physical parameters. Thus, optimizing the second-stage electrode will help control the thrust. Lastly, a special cathode feeding was developed to increase the lifetime of the μCAT-MPD thruster. The results of this dissertation led to the development of an advanced micro cathode vacuum arc thruster, a high thrust-to-power and high efficiency multi-modal low power micro propulsive device.
- All rights reserved
Notice to Authors
If you are the author of this work and you have any questions about the information on this page, please use the Contact form to get in touch with us.