Laser-Induced Fluorescence Velocity Measurements of a Low Power Cylindrical Hall Thruster
Abstract
This work presents a preliminary survey of the axial velocities within the acceleration channel and axial, radial and azimuthal velocities in the plume of a Princeton University low power cylindrical Hall thruster. Xenon ion velocities for the thruster are derived from laser-induced fluorescence measurements of the 5d[4]7/2-6p[3]5/2 xenon ion excited state transition. Three operating conditions are considered with variations to the magnetic field strength and chamber background pressure in an effort to capture their effects on ion acceleration and centerline ion energy distributions. Under nominal conditions, xenon ions are accelerated to an energy of 25 eV within the thruster with an additional 188 eV gain in the thruster plume. At a position 40 mm into the plume, this constitutes an energy of 213 eV at an applied potential of 300 V. Decreasing the magnetic field strength appears to reduce the magnitude of radial ion velocities and pushes the peak electric field downstream into the plume. Increasing the background pressure is shown to reduce the plume divergence, move the peak electric field upstream towards the thruster exit plane, and result in a higher centerline axial ion velocity in the far-field of the plume.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 25, 2009
- Accession Number
- ADA506823
Entities
People
- Mark Cappelli
- Natalia A. Macdonald
- William A. Hargus
Organizations
- Air Force Research Laboratory