Experimental and gyrokinetic studies of impurity transport in the core of Alcator C-Mod Plasmas

[摘要] Using a unique set of diagnostics and modeling tools, a comprehensive study of impurity transport was performed on Alcator C-Mod L-mode discharges. A new, multi-pulse laser blow-off system was designed and constructed to introduce trace amounts of non-recycling, non-intrinsic, impurities in the plasma edge. This system was coupled with an x-ray crystal spectrometer, a single chord x-ray/ultraviolet spectrometer, and measurement of the laser blow-off neutral source at the plasma edge to provide full, time-evolving, radial profiles of a single impurity charge state. An iterative X2 minimization scheme was created to infer the experimental impurity transport coefficients and their uncertainty by minimizing the difference in the measured and STRAHL simulated emission. These measurements and data analysis methodology allowed for determination of impurity transport coefficient profiles with realistic errors from 0.0

[发布机构] Massachusetts Institute of Technology