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Title: Relative intensity calibration of the DIII-D charge-exchange recombination spectroscopy system using neutral beam injection into gas

Abstract

A new calibration method for the DIII-D charge-exchange spectroscopy system produces a smoother impurity density profile compared to previous techniques, thus improving the accuracy of the impurity density profile reconstruction. The relative intensity calibration between the chords of the DIII-D charge-exchange recombination spectroscopy system is performed by firing neutral beams into the evacuated vacuum vessel pre-filled with neutral gas. Relative calibration is required in order to account for uncertainty in the 3D geometry of the neutral beam. Previous methods using helium gas have been improved by using xenon, which emits an emission line close to the commonly used carbon wavelength 5290.5 Å, as well as improved timing of the gas injection, inclusion of variations in the vessel pressure, and timing of neutral beam injection. Photoemission spectra recorded by 112 sightlines viewing 6 neutral beams are compared and used to form a relative calibration factor for each sightline. This relative calibration is shown to improve the quality of the measured ion density profile.

Authors:
 [1]; ORCiD logo [2]; ORCiD logo [2]; ORCiD logo [1]
  1. Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
  2. General Atomics, San Diego, CA (United States)
Publication Date:
Research Org.:
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1474417
Alternate Identifier(s):
OSTI ID: 1470804
Grant/Contract Number:  
FC02-04ER54698; AC02-09CH11466
Resource Type:
Accepted Manuscript
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 89; Journal Issue: 10; Journal ID: ISSN 0034-6748
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; charge exchange reactions; plasma confinement; tokamaks; charge coupled devices; charge exchange recombination spectroscopy

Citation Formats

Grierson, B. A., Burrell, K. H., Chrystal, C., and Haskey, S. R. Relative intensity calibration of the DIII-D charge-exchange recombination spectroscopy system using neutral beam injection into gas. United States: N. p., 2018. Web. doi:10.1063/1.5037333.
Grierson, B. A., Burrell, K. H., Chrystal, C., & Haskey, S. R. Relative intensity calibration of the DIII-D charge-exchange recombination spectroscopy system using neutral beam injection into gas. United States. doi:https://doi.org/10.1063/1.5037333
Grierson, B. A., Burrell, K. H., Chrystal, C., and Haskey, S. R. Fri . "Relative intensity calibration of the DIII-D charge-exchange recombination spectroscopy system using neutral beam injection into gas". United States. doi:https://doi.org/10.1063/1.5037333. https://www.osti.gov/servlets/purl/1474417.
@article{osti_1474417,
title = {Relative intensity calibration of the DIII-D charge-exchange recombination spectroscopy system using neutral beam injection into gas},
author = {Grierson, B. A. and Burrell, K. H. and Chrystal, C. and Haskey, S. R.},
abstractNote = {A new calibration method for the DIII-D charge-exchange spectroscopy system produces a smoother impurity density profile compared to previous techniques, thus improving the accuracy of the impurity density profile reconstruction. The relative intensity calibration between the chords of the DIII-D charge-exchange recombination spectroscopy system is performed by firing neutral beams into the evacuated vacuum vessel pre-filled with neutral gas. Relative calibration is required in order to account for uncertainty in the 3D geometry of the neutral beam. Previous methods using helium gas have been improved by using xenon, which emits an emission line close to the commonly used carbon wavelength 5290.5 Å, as well as improved timing of the gas injection, inclusion of variations in the vessel pressure, and timing of neutral beam injection. Photoemission spectra recorded by 112 sightlines viewing 6 neutral beams are compared and used to form a relative calibration factor for each sightline. This relative calibration is shown to improve the quality of the measured ion density profile.},
doi = {10.1063/1.5037333},
journal = {Review of Scientific Instruments},
number = 10,
volume = 89,
place = {United States},
year = {2018},
month = {9}
}

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