ABSTRACT The design of the magnetic field is crucial to performance hall thruster. This paper investigates effects on discharge characteristics low-power thruster in method combining simulation and experiment. Based a 40-mm-diameter (LHT-40) operating with hundreds Watts, two-dimensional axisymmetric model established fluid investigate mechanism, how influences thruster, experiments are also ca...

A thrust stand was modified, and a primary calibration technique was developed to evaluate the performance of applied-field pulsed magnetoplasmadynamic thrusters (MPDTs) for 10 kW class solar electric orbit transfer vehicle (SEOTV) missions. The NASA Lewis Research Center (LeRC) 30 kW thrust stand was modified to accept high current pulses delivered to the MPDT. A pendulum system was developed ...

The performance of Hall thrusters can be highly sensitive to the position and operational parameters of the external cathode, hinting that the electron transport in the near-field is strongly dependent on the emitted electrons’ initial properties. In addition, the plasma plumes of Hall discharges often exhibit fluctuations which are expected to alter electron trajectories. By implementing recen...

The performance and the plasma created by a pulsed magnetoplasmadynamic thruster for small satellite application is studied to understand better the ablation and plasma propagation processes occurring during the short-time discharge. The results can be applied to improve the quality of the thruster in terms of efficiency, and to tune the propulsion system to the needs required by the satellite ...

A Faraday probe with three concentric rings was designed and fabricated to assess the effect of gap width and collector diameter in a systematic study of the diagnostic ion collection area. The nested Faraday probe consisted of two concentric collector rings and an outer guard ring, which enabled simultaneous current density measurements on the inner and outer collectors. Two versions of the ou...

The effects of anode temperature on the performance of a 4.5 kW Hall-effect thruster are investigated. The approach separates the location of gas injection from discharge current collection using an anode band, which removes the main mechanism that heats the gas distributor. A thermal model predicts a 270 K reduction of the gas distributor temperature, which corresponds to a 28% increase in the...

We present laser-induced fluorescence velocimetry measurements obtained using the Xe I 6s[3/2]2 → 6p[3/2]2 transition at 823.4 nm (vacuum) and the Xe I 6s’[1/2]1 → 6p’[3/2]2 transition at 834.9 nm (vacuum) from the inside and in the near-field plume of a 6-kW Hall thruster. The thruster is operated under seven conditions with discharge voltages ranging from 150 to 600 V, and anode mass flow rat...

A micro-thrust stand developed by the National Physical Laboratory under ESA funding was calibrated and characterized. The balance is based on the nulled-pendulum principle. The thruster is positioned in a constrained pendulum that is free to move only along the line of thrust. A capacitive displacement sensor measures the movement of the pendulum and is connected via a servo closed loop to a f...

We present a control algorithm for autonomous underwater robots with modular thruster configuration. The algorithm can handle arbitrary thruster configurations. It maintains the robot’s desired attitude while solving for translational motion. The attitude can be arbitrarily chosen from the special orthogonal group SO allowing the robot all possible orientations. The desired translational veloci...

This paper reports an experimental investigation of the effect of two specific errors on a class of model based controllers for the low-speed maneuvering of fully actuated underwater vehicles. First, we review previously reported studies and a commonly accepted simplified plant model that has been experimentally validated for this class of vehicles. Second, we review a family of associated mode...