Measurement of erosion rate by absorption spectroscopy in a Hall thruster

Abstract

Articles you may be interested inA cavity ring-down spectroscopy sensor for real-time Hall thruster erosion measurements Rev. Sci. Instrum. 85, 053111 (2014); 10.1063/1.4879135 Electron density and energy distribution function in the plume of a Hall-type thruster Rev. Sci. Instrum. 73, 931 (2002); Electron energy distribution function in a Hall-type thruster (abstract) Rev. Sci. Instrum. 71, 731 (2000)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 Al x In y Ga ͑1−x−y͒ N diode laser was used as the probe. The estimated number density of iron was 1.1ϫ 10 16 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.

Development of vacuum ultraviolet absorption spectroscopy system for wide measurement range of number density using a dual-tube inductively coupled plasma light source

“…Equations (1)- (4) show that I t /I 0 depends not only on Kl, but also on T of the light source and the target.…”

“…Atomic species in plasma are important in several fields such as the oxidation of materials, 1 chamber cleaning, 2 organic polymer etching, 3 space propulsion, 4 and thermal protection systems for entry vehicles. 5 In these varied fields, however, no established method is yet available to measure these number densities.…”

Measurement of Aluminum Erosion Rate by Cavity Ring-Down Spectroscopy

“…It is difficult, however, to make direct quantitative number density measurements of sputtered particles from LIF. LAS is used for measuring absolute number density of the sputtered particles in some electric propulsion devices, 3) but the sensitivity of the technique is not sufficient to detect the density of eroded particles from the acceleration grid of an ion thruster. Cavity Ring-Down Spectroscopy (CRDS) can measure absolute number density with high sensitivity and it is suitable for measuring the number density of sputtered particles from the acceleration grid.…”

Development of Real-time Erosion Monitoring System for Hall Thrusters by Cavity Ring-Down Spectroscopy

“…A key requirement for the practical use of Hall thrusters is the ability to operate for long durations, for example a Hall thruster used for north-south station keeping (NSSK) of a commercial spacecraft will have to operate for over 5,000 hours over the course of its mission 4,5) . The primary life-limiter for Hall thrusters is acceleration channel wall erosion 6,7) . A thruster is generally considered to have reached end of life when the channel is fully eroded and the underlying magnetic yoke becomes exposed.…”