Joint Laboratory
Plasma and Propulsion


A new paper is published on Acta Astronautica

A doctoral candidate member in JLPP, Zhongkai Zhang, whose article has been published on Acta Astronautica. The title of this article is Roll torque measurement and interpretation of low power Hall-effect thrusters.


In this work, a novel method of directly measuring the roll torque of low power Hall-effect thrusters is proposed. The measurement device uses an elastic pendulum with the thruster mounted on the same axis as the rotation axis of the pendulum, and the torque of the thruster is reflected in the rotation of the movement part and amplified by the pendulum arm with the measuring range of approximately 0 to 200 μN·m with a resolution of less than 0.5 μN·m. The roll torque measurement results of a Hall-effect thruster show that the rotational direction is consistent with the ion deflection direction by the magnetic field, and the roll torque ranges about 16 – 23 μN·m at the anode power range of 300 – 450 W with cathode keeper, and the values is influenced by the cathode keeper currents. An empirical formula for the Hall-effect thrusters is proposed according to the reliable measurement results of the low power Hall-effect thruster, and the roll torque values are estimated for several low power to medium power Hall-effect thrusters. The method also provides a new idea to accurately evaluate the roll torque of other types of electric propulsion thrusters.

Schematic diagram of the torsional pendulum roll torque measurement device.

(a) The magnetic field lines and direction in the Hall-effect thruster channel, (b) pendulum rotation due to thruster torque during ignition, and (c) the signal response of the displacement sensor.


Link: Roll torque measurement and interpretation of low power Hall-effect thrusters

Editor: Ruojian Pan