Erosion rate diagnostics in ion thrusters using laser-induced fluorescence
| Autor: | John D. Williams, W. S. Williamson, C. J. Gaeta, R. S. Turley, J. R. Beattie, Jesse N. Matossian |
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| Rok vydání: | 1993 |
| Předmět: |
Materials science
Ion beam Ion thruster Mechanical Engineering Aerospace Engineering chemistry.chemical_element Laser law.invention Ion Condensed Matter::Materials Science Fuel Technology Xenon Ion beam deposition chemistry Physics::Plasma Physics Space and Planetary Science law Molybdenum Physics::Atomic and Molecular Clusters Atomic physics Laser-induced fluorescence |
| Zdroj: | Journal of Propulsion and Power. 9:369-376 |
| ISSN: | 1533-3876 0748-4658 |
| Popis: | We have used laser-induced fluorescence (LIF) to monitor the charge-exchange ion erosion of the molybdenum accelerator electrode in ion thrusters. This real-time, nonintrusive method was implemented by operating a 30cm-diam ring-cusp thruster using xenon propellant. With the thruster operating at a total power of 5 kW, laser radiation at a wavelength of 390 nm (corresponding to a ground state atomic transition of molybdenum) was directed through the extracted ion beam adjacent to the downstream surface of the molybdenum accelerator electrode. Molybdenum atoms, sputtered from this surface as a result of charge-exchange ion erosion, were excited by the laser radiation. The intensity of the laser-induced fluorescence radiation, which is proportional to the sputter rate of the molybdenum atoms, was measured and correlated with variations in thruster operating conditions such as accelerator electrode voltage, accelerator electrode current, and test facility background pressure. We also demonstrated that the LIF technique has sufficient sensitivity and spatial resolution to evaluate accelerator electrode lifetime in ground-based test facilities. |
| Databáze: | OpenAIRE |
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