Predicted performance of a tangential viewing hard x-ray camera for the DIII-D high field side lower hybrid current drive experiment
Name
5.0099168.pdf
Description
Published version
Size
7.58 MB
Format
Adobe PDF
Checksum (MD5)
3a3a0a85d6e6c949977ab5cdf468f58a
Author(s)
Rutherford, Grant
Seltzman, Andrew H
Wukitch, Stephen J
Date Issued
October 1, 2022
Journal
Review of Scientific Instruments
Publisher
AIP Publishing
Citation
Rutherford, Grant, Seltzman, Andrew H and Wukitch, Stephen J. 2022. "Predicted performance of a tangential viewing hard x-ray camera for the DIII-D high field side lower hybrid current drive experiment." Review of Scientific Instruments, 93 (10).
Version
Final published version
Abstract
High field side launch of lower hybrid current drive (LHCD) has improved accessibility and penetration over low field side launch on DIII-D. Simulations predict single pass absorption under a wide range of plasma conditions. Hard x-ray (HXR) measurement of LHCD generated fast electron bremsstrahlung (50–250 keV) will validate wave propagation and absorption. Emissivity profiles are recovered from one-dimensional inversion of HXR brightness to determine LH damping location, fast electron slowing down time, and some indication of the fast electron energy. The camera will be implemented by populating 32 tangential sightlines of the existing Gamma Ray Imager with Kromek SPEARTM Cadmium Zinc Telluride (CZT) detectors sensitive to 10–1000 keV photons with 10 keV energy resolution. Expected count rates allow for <0.5 ms time resolution. Pulses are processed using 50 ns shaping time Cremat CR-200 Gaussian shaping modules and are digitized by 25 MHz D-TACQ ACQ216 digitizers. The performance of the HXR camera is evaluated by comparing predicted fast electron density profiles and inverted synthetic brightnesses obtained from the ray-tracing/Fokker–Planck codes GENRAY/CQL3D. Inversions closely matched predicted fast electron profiles for a range of experimental parameters.
MIT Department
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Terms of Use
Creative Commons Attribution 4.0 International license
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DOI of Published Version
https://doi.org/10.1063/5.0099168
