Laser-induced Fluorescence Measurements of Energetic Ions in High Current Hollow Cathodes

Chris Dodson Benjamin Jorns Richard Wirz

This project investigates the existence of high energy ions generated in high current hollow cathode plumes using Laser Induced Fluorescence (LIF) and plasma probes. Ion acoustic turbulence is generated from a high electron to ion relative drift velocity, and wave-particle interactions lead to heating of plasma in the plume. Energetic ions can cause erosion of cathode surfaces used for long duration missions using Hall thrusters. We test a 100 A-class hollow cathode at JPL and perform LIF measurements to study the formation of energetic ions and the evolution of the IVDF in the plume. Ongoing studies include analytical and computational approaches to model the wave heating mechanisms.

[1] Christopher Dodson, Daniel Perez-Grande, Benjamin Jorns, Dan M. Goebel, and Richard E. Wirz. "Laser-induced Fluorescence Measurements of Energetic Ions in a 100-A LaB6 Hollow Cathode Plume", 52nd AIAA/SAE/ASEE Joint Propulsion Conference, Propulsion and Energy Forum, (AIAA 2016-4838)