2D imaging of helium ion velocity in the DIII-D divertor

Samuell, C. M.; Porter, G. D.; Meyer, W. H.; Rognlien, T. D.; Allen, S. L.; Briesemeister, A.; Mclean, A. G.; Zeng, L.; Jaervinen, A. E.; Howard, J.

doi:10.1063/1.5017999

Title: 2D imaging of helium ion velocity in the DIII-D divertor

Abstract

Two-dimensional imaging of parallel ion velocities are compared to fluid modeling simulations to understand the role of ions in determining divertor conditions and benchmark the UEDGE fluid modeling code. Pure helium discharges are used so that spectroscopic He+measurements represent the main-ion population at small electron temperatures. Electron temperatures and densities in the divertor match simulated values to within about 20-30% establishing the experiment/model match as being at least as good as those normally obtained in the more regularly simulated deuterium plasmas. He⁺ brightness (HeII) comparison indicates that the degree of detachment is captured well by UEDGE, principally due to the inclusion of E x B drifts. Tomographically inverted Coherence Imaging Spectroscopy (CIS) measurements are used to determine the He⁺ parallel velocities which display excellent agreement between model and experiment near the divertor target where He⁺ is predicted to be the main-ion species and where electron-dominated physics dictates the parallel momentum balance. Upstream near the X-point where He⁺ is a minority species and ion-dominated physics plays a more important role, there is an underestimation of the flow velocity magnitude by a factor of 2-3. These results indicate that more effort is required to be able to correctly predict ion momentum inmore » these challenging regimes.« less

Authors:

^[1]; Porter, G. D. ^[1]; Meyer, W. H. ^[1]; Rognlien, T. D. ^[1]; Allen, S. L. ^[1];

^[2]; Mclean, A. G. ^[1]; Zeng, L. ^[3]; Jaervinen, A. E. ^[1];

^[4]

Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Univ. of California, Los Angeles, CA (United States)
Australian National Lab. Canberra, ACT (Australia)

Publication Date:: Wed Apr 25 00:00:00 EDT 2018

Research Org.:: General Atomics, San Diego, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:: USDOE National Nuclear Security Administration (NNSA)

OSTI Identifier:: 1568884

Alternate Identifier(s):: OSTI ID: 1434565; OSTI ID: 1491642

Report Number(s):: LLNL-JRNL-744602
Journal ID: ISSN 1070-664X; TRN: US2100333

Grant/Contract Number:: FC02-04ER54698; AC52-07NA27344; AC05-00OR22725

Resource Type:: Accepted Manuscript

Journal Name:: Physics of Plasmas

Additional Journal Information:: Journal Volume: 25; Journal Issue: 5; Journal ID: ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats


                    Samuell, C. M., Porter, G. D., Meyer, W. H., Rognlien, T. D., Allen, S. L., Briesemeister, A., Mclean, A. G., Zeng, L., Jaervinen, A. E., and Howard, J. 2D imaging of helium ion velocity in the DIII-D divertor.  United States: N. p., 2018. 
Web.  doi:10.1063/1.5017999.

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                    Samuell, C. M., Porter, G. D., Meyer, W. H., Rognlien, T. D., Allen, S. L., Briesemeister, A., Mclean, A. G., Zeng, L., Jaervinen, A. E., & Howard, J. 2D imaging of helium ion velocity in the DIII-D divertor.  United States.  https://doi.org/10.1063/1.5017999

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                    Samuell, C. M., Porter, G. D., Meyer, W. H., Rognlien, T. D., Allen, S. L., Briesemeister, A., Mclean, A. G., Zeng, L., Jaervinen, A. E., and Howard, J. Wed .  
"2D imaging of helium ion velocity in the DIII-D divertor".  United States.  https://doi.org/10.1063/1.5017999.  https://www.osti.gov/servlets/purl/1568884.

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@article{osti_1568884,

  title        = {2D imaging of helium ion velocity in the DIII-D divertor},

  author       = {Samuell, C. M. and Porter, G. D. and Meyer, W. H. and Rognlien, T. D. and Allen, S. L. and Briesemeister, A. and Mclean, A. G. and Zeng, L. and Jaervinen, A. E. and Howard, J.},

  abstractNote = {Two-dimensional imaging of parallel ion velocities are compared to fluid modeling simulations to understand the role of ions in determining divertor conditions and benchmark the UEDGE fluid modeling code. Pure helium discharges are used so that spectroscopic He+measurements represent the main-ion population at small electron temperatures. Electron temperatures and densities in the divertor match simulated values to within about 20-30% establishing the experiment/model match as being at least as good as those normally obtained in the more regularly simulated deuterium plasmas. He+ brightness (HeII) comparison indicates that the degree of detachment is captured well by UEDGE, principally due to the inclusion of E x B drifts. Tomographically inverted Coherence Imaging Spectroscopy (CIS) measurements are used to determine the He+ parallel velocities which display excellent agreement between model and experiment near the divertor target where He+ is predicted to be the main-ion species and where electron-dominated physics dictates the parallel momentum balance. Upstream near the X-point where He+ is a minority species and ion-dominated physics plays a more important role, there is an underestimation of the flow velocity magnitude by a factor of 2-3. These results indicate that more effort is required to be able to correctly predict ion momentum in these challenging regimes.},

  doi          = {10.1063/1.5017999},

  journal      = {Physics of Plasmas},

  number       = 5,

  volume       = 25,

  place        = {United States},

  year         = {Wed Apr 25 00:00:00 EDT 2018},

  month        = {Wed Apr 25 00:00:00 EDT 2018}

}

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https://doi.org/10.1063/1.5017999

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Cited by: 11 works

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Figures / Tables:

FIG. 1: Last closed flux surface from EFIT reconstruction for DⅢ-D shot 166821 at 1800 ms (black). Measurement locations for Thompson Scattering (red x), Divertor Thompson Scattering (DTS) (red +), and microwave interferometry profiles (blue triangles) are overlaid. The blue shaded region corresponds to the approximate field of view ofmore »

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Works referenced in this record:

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Zeng, L.; Peebles, W. A.; Doyle, E. J.
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Works referencing / citing this record:

DIII-D research towards establishing the scientific basis for future fusion reactors
journal, June 2019

Petty, C. C.
Nuclear Fusion, Vol. 59, Issue 11
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Summary of the 27th IAEA Fusion Energy Conference in the categories of EX/W, EX/D, and ICC
journal, September 2019

Ida, K.
Nuclear Fusion, Vol. 59, Issue 11
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Direct measurements of counter-streaming flows in a low-shear stellarator magnetic island topology
journal, September 2019

Perseo, V.; Effenberg, F.; Gradic, D.
Nuclear Fusion, Vol. 59, Issue 12
DOI: 10.1088/1741-4326/ab4320

Coherence imaging spectroscopy at Wendelstein 7-X for impurity flow measurements
journal, January 2020

Perseo, Valeria; Gradic, Dorothea; König, Ralf
Review of Scientific Instruments, Vol. 91, Issue 1
DOI: 10.1063/1.5126098

Coherence-imaging spectroscopy for 2D distribution of ion temperature and flow velocity in a laboratory magnetosphere
journal, October 2018

Nakamura, K.; Nishiura, M.; Takahashi, N.
Review of Scientific Instruments, Vol. 89, Issue 10
DOI: 10.1063/1.5037124

Verification of Doppler coherence imaging for 2D ion velocity measurements on DIII-D
journal, September 2018

Samuell, C. M.; Allen, S. L.; Meyer, W. H.
Review of Scientific Instruments, Vol. 89, Issue 9
DOI: 10.1063/1.5039367

Laser calibration of the DIII-D coherence imaging system
journal, October 2018

Allen, S. L.; Samuell, C. M.; Meyer, W. H.
Review of Scientific Instruments, Vol. 89, Issue 10
DOI: 10.1063/1.5038739

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Similar Records

Title: 2D imaging of helium ion velocity in the DIII-D divertor

Abstract

Citation Formats

Figures / Tables:

Performance and data analysis aspects of the new DIII-D monostatic profile reflectometer system journal, November 2014

Understanding the SOL flow in L-mode plasma on divertor tokamaks, and its influence on the plasma transport journal, June 2007

Poloidally and radially resolved parallel D+ velocity measurements in the DIII-D boundary and comparison to neoclassical computations journal, March 2011

Techniques and results of tokamak-edge simulation journal, April 1995

A comparison of experimental measurements and code results to determine flows in the JET SOL journal, September 2004

Flow reversal, convection, and modeling in the DIII-D divertor journal, December 1998

Coherence Imaging of Flows in the DIII-D Divertor journal, March 2011

Two-dimensional electric fields and drifts near the magnetic separatrix in divertor tokamaks journal, May 1999

Doppler coherence imaging and tomography of flows in tokamak plasmas (invited) journal, October 2010

A 3D Monte Carlo code for plasma transport in island divertors journal, February 1997

Comparison of 2D simulations of detached divertor plasmas with divertor Thomson measurements in the DIII-D tokamak journal, August 2017

Transport and drift-driven plasma flow components in the Alcator C-Mod boundary plasma journal, January 2013

Coherence imaging of scrape-off-layer and divertor impurity flows in the Mega Amp Spherical Tokamak (invited) journal, November 2014

Testing the role of molecular physics in dissipative divertor operations through helium plasmas at DIII-D journal, May 2017

Spectroscopic analysis of normal and reversed ion flows in the DIII-D divertor journal, February 1999

Scaling radiative divertor solutions to high power in DIII-D journal, April 2012

A fully implicit, time dependent 2-D fluid code for modeling tokamak edge plasmas journal, December 1992

Effect of cross-field drifts on flows in the main scrape-off-layer of DIII-D L-mode plasmas journal, September 2009

Plasma Edge Physics with B2-Eirene journal, February 2006

DIII-D research towards establishing the scientific basis for future fusion reactors journal, June 2019

Summary of the 27th IAEA Fusion Energy Conference in the categories of EX/W, EX/D, and ICC journal, September 2019

Direct measurements of counter-streaming flows in a low-shear stellarator magnetic island topology journal, September 2019

Coherence imaging spectroscopy at Wendelstein 7-X for impurity flow measurements journal, January 2020

Coherence-imaging spectroscopy for 2D distribution of ion temperature and flow velocity in a laboratory magnetosphere journal, October 2018

Verification of Doppler coherence imaging for 2D ion velocity measurements on DIII-D journal, September 2018

Laser calibration of the DIII-D coherence imaging system journal, October 2018

Performance and data analysis aspects of the new DIII-D monostatic profile reflectometer system
journal, November 2014

Understanding the SOL flow in L-mode plasma on divertor tokamaks, and its influence on the plasma transport
journal, June 2007

Poloidally and radially resolved parallel D+ velocity measurements in the DIII-D boundary and comparison to neoclassical computations
journal, March 2011

Techniques and results of tokamak-edge simulation
journal, April 1995

A comparison of experimental measurements and code results to determine flows in the JET SOL
journal, September 2004

Flow reversal, convection, and modeling in the DIII-D divertor
journal, December 1998

Coherence Imaging of Flows in the DIII-D Divertor
journal, March 2011

Two-dimensional electric fields and drifts near the magnetic separatrix in divertor tokamaks
journal, May 1999

Doppler coherence imaging and tomography of flows in tokamak plasmas (invited)
journal, October 2010

A 3D Monte Carlo code for plasma transport in island divertors
journal, February 1997

Comparison of 2D simulations of detached divertor plasmas with divertor Thomson measurements in the DIII-D tokamak
journal, August 2017

Transport and drift-driven plasma flow components in the Alcator C-Mod boundary plasma
journal, January 2013

Coherence imaging of scrape-off-layer and divertor impurity flows in the Mega Amp Spherical Tokamak (invited)
journal, November 2014

Testing the role of molecular physics in dissipative divertor operations through helium plasmas at DIII-D
journal, May 2017

Spectroscopic analysis of normal and reversed ion flows in the DIII-D divertor
journal, February 1999

Scaling radiative divertor solutions to high power in DIII-D
journal, April 2012

A fully implicit, time dependent 2-D fluid code for modeling tokamak edge plasmas
journal, December 1992

Effect of cross-field drifts on flows in the main scrape-off-layer of DIII-D L-mode plasmas
journal, September 2009

Plasma Edge Physics with B2-Eirene
journal, February 2006

DIII-D research towards establishing the scientific basis for future fusion reactors
journal, June 2019

Summary of the 27th IAEA Fusion Energy Conference in the categories of EX/W, EX/D, and ICC
journal, September 2019

Direct measurements of counter-streaming flows in a low-shear stellarator magnetic island topology
journal, September 2019

Coherence imaging spectroscopy at Wendelstein 7-X for impurity flow measurements
journal, January 2020

Coherence-imaging spectroscopy for 2D distribution of ion temperature and flow velocity in a laboratory magnetosphere
journal, October 2018

Verification of Doppler coherence imaging for 2D ion velocity measurements on DIII-D
journal, September 2018

Laser calibration of the DIII-D coherence imaging system
journal, October 2018