Hall Thruster Erosion Measurement

The problem:

Hall thrusters have the potential to provide a cost-effective alternative to conventional chemical-based propulsion systems for maintaining satellite orbits and conducting deep-space exploration. One of the critical factors affecting their long term performance is the erosion of the ceramic components in the discharge chamber. However, the confined annular space of the anode makes it difficult to quantitatively monitor the surface geometry.

The solution:

LTC's laser profiling sensors are ideal for applications where precise measurements must be made in a confined space. Unlike typical laser-based surface mapping systems that project a line or spot from a large external source, LTC's LP sensors use laser diodes and miniature optics, making them small enough to reach inside the annular cavity. In addition, the LaserVideo™ image dataset from the laser sensor provides valuable qualitative information about the surface condition.

For more information about laser-based mapping and how it works, see our laser profile mapping technology page.

The details:

The US Air Force recently contracted with LTC to adapt the Laser MicroMap™ system to provide three-dimensional maps of both the conical "inner guard ring" and the cylindrical "outer guard ring" of a developmental Hall thruster. LTC provided a system with a custom laser profiling sensor and a three-axis stage-based delivery mechanism, combined with our standard LP-2000™ Control Unit and LaserViewer™ software. This system was able to map virtually 100% of the anode surface, with a spatial resolution of 0.001 inch (0.025 mm) and a depth resolution of 0.0002 inch (0.005 mm).

The images below show scan data that has been imported into MATLAB™.

More information regarding Hall thruster erosion measurement (Adobe Reader required.)