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 »
- Authors:
-
- 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:
- 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.
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
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.
@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}
}
Web of Science
Figures / Tables:
Works referenced in this record:
Performance and data analysis aspects of the new DIII-D monostatic profile reflectometer system
journal, November 2014
- Zeng, L.; Peebles, W. A.; Doyle, E. J.
- Review of Scientific Instruments, Vol. 85, Issue 11
Understanding the SOL flow in L-mode plasma on divertor tokamaks, and its influence on the plasma transport
journal, June 2007
- Asakura, Nobuyuki
- Journal of Nuclear Materials, Vol. 363-365
Poloidally and radially resolved parallel D+ velocity measurements in the DIII-D boundary and comparison to neoclassical computations
journal, March 2011
- Boedo, J. A.; Belli, E. A.; Hollmann, E.
- Physics of Plasmas, Vol. 18, Issue 3
Techniques and results of tokamak-edge simulation
journal, April 1995
- Smith, G. R.; Brown, P. N.; Campbell, R. B.
- Journal of Nuclear Materials, Vol. 220-222
A comparison of experimental measurements and code results to determine flows in the JET SOL
journal, September 2004
- Erents, S. K.; Pitts, R. A.; Fundamenski, W.
- Plasma Physics and Controlled Fusion, Vol. 46, Issue 11
Flow reversal, convection, and modeling in the DIII-D divertor
journal, December 1998
- Boedo, J. A.; Porter, G. D.; Schaffer, M. J.
- Physics of Plasmas, Vol. 5, Issue 12
Coherence Imaging of Flows in the DIII-D Divertor
journal, March 2011
- Howard, J.; Diallo, A.; Creese, M.
- Contributions to Plasma Physics, Vol. 51, Issue 2-3
Two-dimensional electric fields and drifts near the magnetic separatrix in divertor tokamaks
journal, May 1999
- Rognlien, T. D.; Ryutov, D. D.; Mattor, N.
- Physics of Plasmas, Vol. 6, Issue 5
Doppler coherence imaging and tomography of flows in tokamak plasmas (invited)
journal, October 2010
- Howard, J.; Diallo, A.; Creese, M.
- Review of Scientific Instruments, Vol. 81, Issue 10
A 3D Monte Carlo code for plasma transport in island divertors
journal, February 1997
- Feng, Y.; Sardei, F.; Kisslinger, J.
- Journal of Nuclear Materials, Vol. 241-243
Comparison of 2D simulations of detached divertor plasmas with divertor Thomson measurements in the DIII-D tokamak
journal, August 2017
- Rognlien, T. D.; McLean, A. G.; Fenstermacher, M. E.
- Nuclear Materials and Energy, Vol. 12
Transport and drift-driven plasma flow components in the Alcator C-Mod boundary plasma
journal, January 2013
- Smick, N.; LaBombard, B.; Hutchinson, I. H.
- Nuclear Fusion, Vol. 53, Issue 2
Coherence imaging of scrape-off-layer and divertor impurity flows in the Mega Amp Spherical Tokamak (invited)
journal, November 2014
- Silburn, S. A.; Harrison, J. R.; Howard, J.
- Review of Scientific Instruments, Vol. 85, Issue 11
Testing the role of molecular physics in dissipative divertor operations through helium plasmas at DIII-D
journal, May 2017
- Canik, J. M.; Briesemeister, A. R.; McLean, A. G.
- Physics of Plasmas, Vol. 24, Issue 5
Spectroscopic analysis of normal and reversed ion flows in the DIII-D divertor
journal, February 1999
- Isler, R. C.; Brooks, N. H.; West, W. P.
- Physics of Plasmas, Vol. 6, Issue 2
Scaling radiative divertor solutions to high power in DIII-D
journal, April 2012
- Leonard, A. W.; Mahdavi, M. A.; Lasnier, C. J.
- Nuclear Fusion, Vol. 52, Issue 6
A fully implicit, time dependent 2-D fluid code for modeling tokamak edge plasmas
journal, December 1992
- Rognlien, T. D.; Milovich, J. L.; Rensink, M. E.
- Journal of Nuclear Materials, Vol. 196-198
Effect of cross-field drifts on flows in the main scrape-off-layer of DIII-D L-mode plasmas
journal, September 2009
- Groth, M.; Boedo, J. A.; Brooks, N. H.
- Nuclear Fusion, Vol. 49, Issue 11
Plasma Edge Physics with B2-Eirene
journal, February 2006
- Schneider, R.; Bonnin, X.; Borrass, K.
- Contributions to Plasma Physics, Vol. 46, Issue 1-2
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
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
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
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
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
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
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
Figures / Tables found in this record: