Measurement of erosion rate by absorption spectroscopy in a Hall thruster

Abstract

The erosion rate of a Hall thruster was estimated with the objective of building a real-time erosion rate monitoring system using a 1 kW class anode layer type Hall thruster. This system aids the understanding of the tradeoff between lifetime and performance. To estimate the flux of the sputtered wall material, the number density of the sputtered iron was measured by laser absorption spectroscopy using an absorption line from ground atomic iron at 371.9935 nm. An ultraviolet AlxInyGa(1-x-y)N diode laser was used as the probe. The estimated number density of iron was 1.1 × 1016 m-3, which is reasonable when compared with that measured by duration erosion tests. The relation between estimated erosion rate and magnetic flux density also agreed with that measured by duration erosion tests. © 2005 American Institute of Physics.