Modeling fast charge exchange recombination spectroscopy measurements from the Madison Symmetric Torus
- Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)
Charge exchange recombination spectroscopy measurements of impurity ion temperature (T{sub i}) and velocity (v{sub i}) on the Madison Symmetric Torus present a unique challenge due to two coupled effects: low temperature--typically 300-500 eV, though up to 2 keV in high current plasmas--and a dominant contribution from background, i.e., non charge exchange driven, emission. For low T{sub i}, the background emission line shape is significantly asymmetric as a result of spin-orbit coupling effects. Accurate modeling of both the background and beam emission is therefore required to obtain precise values for local ion parameters. A model has been developed to provide robust simulation of the experimental measurements with {approx}10 {mu}s temporal resolution using atomic data obtained from the Atomic Data and Analysis Structure database. Measurements are made using C VI emission at 343.4 nm, with background and beam emissions obtained simultaneously using two fiber bundles with slightly displaced lines of sight. Emission from O VI contributes substantially to the background signal, and is included in the modeling. A complete description of the model will be presented, along with results for T{sub i} measurements during magnetic reconnection.
- OSTI ID:
- 20861307
- Journal Information:
- Review of Scientific Instruments, Vol. 77, Issue 10; Other Information: DOI: 10.1063/1.2219412; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
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