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Title: Two-dimensional AXUV-based radiated power density diagnostics on NSTX-U

Journal Article · · Review of Scientific Instruments
DOI:https://doi.org/10.1063/1.4890254· OSTI ID:22303702
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  1. MIT - Plasma Science and Fusion Center, Cambridge, Massachusetts 02139 (United States)
  2. Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States)
  3. The Johns Hopkins University, Baltimore, Maryland 21209 (United States)

A new set of radiated-power-density diagnostics for the National Spherical Torus Experiment Upgrade (NSTX-U) tokamak have been designed to measure the two-dimensional poloidal structure of the total photon emissivity profile in order to perform power balance, impurity transport, and magnetohydrodynamic studies. Multiple AXUV-diode based pinhole cameras will be installed in the same toroidal angle at various poloidal locations. The local emissivity will be obtained from several types of tomographic reconstructions. The layout and response expected for the new radially viewing poloidal arrays will be shown for different impurity concentrations to characterize the diagnostic sensitivity. The radiated power profile inverted from the array data will also be used for estimates of power losses during transitions from various divertor configurations in NSTX-U. The effect of in-out and top/bottom asymmetries in the core radiation from high-Z impurities will be addressed.

OSTI ID:
22303702
Journal Information:
Review of Scientific Instruments, Vol. 85, Issue 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
Country of Publication:
United States
Language:
English