Ion Velocity Distribution in a Low-Power Cylindrical Hall Thruster
Abstract
This work presents time-averaged ion velocity and energy distributions in the axial direction within the acceleration channel and axial and radial directions in the plume of a Princeton University low power cylindrical Hall thruster operating on xenon. 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 at λ = 843.72 nm. Two operating conditions are considered with variations to the magnetic field strength, in an effort to capture the effect on ion velocity distributions. The lower magnetic field condition is also considered with a higher vacuum chamber background pressure. Under nominal conditions, xenon ions are accelerated to a most probable energy of 25 eV within the thruster with an additional 175 eV gain in the thruster plume. At a position 40 mm into the plume, this constitutes an energy of 200 eV, with the wings of the energy distribution extending between 177 and 228 eV at an applied potential of 300 V. Decreasing the magnetic field strength appears to improve axial acceleration. Increasing the background chamber pressure pushes the region of maximum acceleration upstream towards the thruster exit plane.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2010
- Accession Number
- ADA527598
Entities
People
- Mark Cappelli
- Natalia A. Macdonald
- William A. Hargus
Organizations
- Air Force Research Laboratory