Toward achieving longevity of micro cathode thrusters

This paper focuses on the axisymmetric side-feeding micro-cathode arc thruster (CAT), an enhanced version of the side-feeding-based micro-cathode arc thruster designed for improved performance characteristics. The axisymmetric micro-CAT is a feeding-based thruster with multiple radially mounted cathodes (propellant consumed per pulse). The objective was to increase the operational lifetime of the thruster for satellite propulsion applications. The discharge power of the thruster is controlled by varying the voltage and the pulse width of the power-providing unit. Thruster performance was enhanced by adding a ring magnet around the plasma generation region. The ion by arc current percent of about 10.5% with the magnetic field and ion velocity of 30 km/s was obtained. A nominal amount of change in length was observed, indicating the motion of the cathode radially due to the spring feeding mechanism. Last, a record lifetime of 13 × 106 pulses was achieved, demonstrating the effectiveness of the feeding mechanism for the thruster. Furthermore, no obvious limitations for ablation have been observed, suggesting that the thruster has the potential to continue its operation well beyond the recorded number of pulses until the propellant is fully exhausted.