Improved cross-calibration of Thomson scattering and electron cyclotron emission with ECH on DIII-D

Brookman, M. W.; Austin, M. E.; McLean, A. G.; Carlstrom, T. N.; Hyatt, A. W.; Lohr, J.

doi:10.1063/1.4959916

Title: Improved cross-calibration of Thomson scattering and electron cyclotron emission with ECH on DIII-D

Abstract

Thomson scattering (TS) produces n_e profiles from measurement of scattered laser beam intensity. In the case of Rayleigh scattering, it provides a first calibration of the relation n_e / ITS, which depends on many factors (e.g. laser alignment and power, optics, and measurement systems). On DIII-D, the n_e calibration is adjusted for each laser and optic path against an absolute n_e measurement from a density-driven cutoff on the 48 channel 2nd harmonic X-mode electron cyclotron emission (ECE) system. This method has been used to calibrate Thompson densities from the edge to near the core (r/a > 0.15). Application of core electron cyclotron heating improves the quality of cutoff and depth of its penetration into the core. ECH also changes underlying MHD activity. Furthermore, on the removal of ECH power, cutoff penetrates in from the edge to the core and channels fall successively and smoothly into cutoff. This improves the quality of the TS n_e calibration while minimizing wall loading.

Authors:

^[1]; Austin, M. E. ^[2]; McLean, A. G. ^[2]; Carlstrom, T. N. ^[3]; Hyatt, A. W. ^[3]; Lohr, J. ^[3]

Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
General Atomics, San Diego, CA (United States)

Publication Date:: Mon Aug 08 00:00:00 EDT 2016

Research Org.:: General Atomics, San Diego, CA (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Fusion Energy Sciences (FES)

OSTI Identifier:: 1371879

Grant/Contract Number:: FC02-04ER54698; FG03-97ER54415

Resource Type:: Accepted Manuscript

Journal Name:: Review of Scientific Instruments

Additional Journal Information:: Journal Volume: 87; Journal Issue: 11; Related Information: M.W. Brookman, M.E. Austin, A.G. McLean, T.N. Carlstrom, A.W. Hyatt, and J. Lohr, "Improved cross-calibration of Thomson scattering and electron cyclotron emission with ECH on DIII-D", Rev. Sci. Instr. 87, 11E517 (2016); 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; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY

Citation Formats


                    Brookman, M. W., Austin, M. E., McLean, A. G., Carlstrom, T. N., Hyatt, A. W., and Lohr, J. Improved cross-calibration of Thomson scattering and electron cyclotron emission with ECH on DIII-D.  United States: N. p., 2016. 
Web.  doi:10.1063/1.4959916.

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                    Brookman, M. W., Austin, M. E., McLean, A. G., Carlstrom, T. N., Hyatt, A. W., & Lohr, J. Improved cross-calibration of Thomson scattering and electron cyclotron emission with ECH on DIII-D.  United States.  https://doi.org/10.1063/1.4959916

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                    Brookman, M. W., Austin, M. E., McLean, A. G., Carlstrom, T. N., Hyatt, A. W., and Lohr, J. Mon .  
"Improved cross-calibration of Thomson scattering and electron cyclotron emission with ECH on DIII-D".  United States.  https://doi.org/10.1063/1.4959916.  https://www.osti.gov/servlets/purl/1371879.

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@article{osti_1371879,

  title        = {Improved cross-calibration of Thomson scattering and electron cyclotron emission with ECH on DIII-D},

  author       = {Brookman, M. W. and Austin, M. E. and McLean, A. G. and Carlstrom, T. N. and Hyatt, A. W. and Lohr, J.},

  abstractNote = {Thomson scattering (TS) produces ne profiles from measurement of scattered laser beam intensity. In the case of Rayleigh scattering, it provides a first calibration of the relation ne / ITS, which depends on many factors (e.g. laser alignment and power, optics, and measurement systems). On DIII-D, the ne calibration is adjusted for each laser and optic path against an absolute ne measurement from a density-driven cutoff on the 48 channel 2nd harmonic X-mode electron cyclotron emission (ECE) system. This method has been used to calibrate Thompson densities from the edge to near the core (r/a > 0.15). Application of core electron cyclotron heating improves the quality of cutoff and depth of its penetration into the core. ECH also changes underlying MHD activity. Furthermore, on the removal of ECH power, cutoff penetrates in from the edge to the core and channels fall successively and smoothly into cutoff. This improves the quality of the TS ne calibration while minimizing wall loading.},

  doi          = {10.1063/1.4959916},

  journal      = {Review of Scientific Instruments},

  number       = 11,

  volume       = 87,

  place        = {United States},

  year         = {Mon Aug 08 00:00:00 EDT 2016},

  month        = {Mon Aug 08 00:00:00 EDT 2016}

}

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Works referenced in this record:

Calibration of Thomson scattering systems using electron cyclotron emission cutoff data
journal, May 2005

Zhurovich, K.; Mossessian, D. A.; Hughes, J. W.
Review of Scientific Instruments, Vol. 76, Issue 5
DOI: 10.1063/1.1899311

Thomson scattering diagnostic upgrade on DIII-D
journal, October 2010

Ponce-Marquez, D. M.; Bray, B. D.; Deterly, T. M.
Review of Scientific Instruments, Vol. 81, Issue 10
DOI: 10.1063/1.3495759

Particle transport with high power central ECH and ECCD in TCV
journal, September 2001

Weisen, H.; Furno, I.; Team, Tcv
Nuclear Fusion, Vol. 41, Issue 9
DOI: 10.1088/0029-5515/41/9/311

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Title: Improved cross-calibration of Thomson scattering and electron cyclotron emission with ECH on DIII-D

Abstract

Citation Formats

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