Applications of advanced kinetic collisional radiative modeling and Bremsstrahlung emission to quantitative impurity analysis on the National Spherical Torus Experiment

作者：Burgos J M Munoz^*; Tritz K; Stutman D; Bell R E; LeBlanc B P; Sabbagh S A

来源：Physics of Plasmas, 2015, 22(12): 123301.

DOI：10.1063/1.4936953

An advanced kinetic collisional radiative model is used to predict beam into plasma charge-exchange visible and extreme UV (XUV similar to 50 - 700 angstrom) light emission to quantify impurity density profiles on NSTX. This kinetic model is first benchmarked by predicting line-of-sight integrated emission for the visible lambda = 5292.0 angstrom line of carbon (C VI n = 8 -> 7), and comparing these predictions to absolute calibrated measurements from the active CHarge-Exchange Recombination Spectroscopy diagnostic (CHERS) on NSTX. Once benchmarked, the model is used to predict charge-exchange emission for the 182.1 angstrom line of carbon (C VI n = 3 -> 2) that is used to scale Bremsstrahlung continuum emission in the UV/XUV region. The scaled Bremsstrahlung emission is used as a base to estimate an absolute intensity calibration curve of a XUV Transmission Grating-based Imaging Spectrometer (TGIS) diagnostic installed on the National Spherical Torus Experiment (NSTX and upgrade NSTX-U). The TGIS diagnostic operates in the wavelength region similar to 50 - 700 angstrom, and it is used to measure impurity spectra from charge-exchange emission. Impurity densities are estimated by fitting synthetic emission from the kinetic charge-exchange model to TGIS spectral measurements.

• 出版日期2015-12