Laser-Induced Fluorescence Measurements within a Laboratory Hall Thruster (Postprint)

摘要

In this paper, we describe the results of a study of laser induced fluorescence velocimetry of ionic xenon in the plume and interior acceleration channel of a laboratory Hall type thruster operating at powers ranging from 250 to 725 W. Optical access to the interior of the Hall thruster is provided by a 1 mm axial slot in the insulator outer wall. Axial ion velocity profiles for four discharge voltages (100 V, 160 V, 200 V, 250 V) are measured as are radial velocity profiles in the near field plume. Internal neutral xenon axial velocity profiles are also measured at these conditions. For each test condition, the implied axial electric field is calculated from the measured ionic velocity profiles. These results are compared to previous plasma potential measurements performed with an emissive probe. The correspondence between the two sets of measurements indicates that the ionization and acceleration regions within the thruster are separated to some degree.