Experimental validation of a model for particle recycling and tungsten erosion during ELMs in the DIII-D divertor

Abrams, T.; Unterberg, E. A.; McLean, A. G.; Rudakov, D. L.; Wampler, W. R.; Knolker, M.; Lasnier, C.; Leonard, A. W.; Stangeby, P. C.; Thomas, D. M.; Wang, H. Q.

doi:10.1016/j.nme.2018.10.011

Title: Experimental validation of a model for particle recycling and tungsten erosion during ELMs in the DIII-D divertor

Abstract

A refined version of the Fundamenksi-Moulton 'free-streaming' model (FSM) for the dynamics of divertor density, particle flux, and heat flux during edge localized modes (ELMs) is presented. This model depends only on inter-ELM pedestal and divertor conditions and, crucially, incorporates particle recycling: a FSM with recycling model, FSRM. The effective particle recycling coefficient, R_eff, is the only empirical fitting parameter in the FSRM. The predictions of the FSRM are systematically tested against a DIII-D database of ELM ion and energy fluence measurements and are shown to be consistent with the model across a wide range of pedestal and divertor conditions using a constant value of 0.96 for R_eff. Predictions for W sputtering during ELMs are developed based on the FSRM. It is concluded that energetic free-streaming D⁺ ions and C⁶⁺ impurities are the dominant contributors to the intra-ELM gross erosion of W in the DIII-D divertor, i.e., recycling ions and impurities have relatively little impact on the total W sputtering rate. Furthermore, these calculations are also shown to be consistent with spectroscopic measurements of W gross erosion for three different pedestal conditions after incorporating the strong electron density dependence of the WI 400.8 nm ionizations/photon (S/XB) coefficient.

Authors:

Abrams, T.;

; McLean, A. G.; Rudakov, D. L.; Wampler, W. R.;

; Lasnier, C.; Leonard, A. W.; Stangeby, P. C.; Thomas, D. M.; Wang, H. Q.

Publication Date:: Sat Dec 01 00:00:00 EST 2018

Research Org.:: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC)

OSTI Identifier:: 1481034

Alternate Identifier(s):: OSTI ID: 1482814; OSTI ID: 1528702; OSTI ID: 1890826

Report Number(s):: LLNL-JRNL-839095
Journal ID: ISSN 2352-1791; S2352179118300772; PII: S2352179118300772

Grant/Contract Number:: FC02-04ER54698; AC52-07NA27344; AC05-00OR22725; FG02-07ER54917

Resource Type:: Published Article

Journal Name:: Nuclear Materials and Energy

Additional Journal Information:: Journal Name: Nuclear Materials and Energy Journal Volume: 17 Journal Issue: C; Journal ID: ISSN 2352-1791

Publisher:: Elsevier

Country of Publication:: Netherlands

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; Tungsten sputtering; Tungsten Erosion; WI spectroscopy; Edge Localized Modes; Recycling; tungsten sputtering; tungsten erosion; edge localized modes; recycling

Citation Formats


                    Abrams, T., Unterberg, E. A., McLean, A. G., Rudakov, D. L., Wampler, W. R., Knolker, M., Lasnier, C., Leonard, A. W., Stangeby, P. C., Thomas, D. M., and Wang, H. Q. Experimental validation of a model for particle recycling and tungsten erosion during ELMs in the DIII-D divertor.  Netherlands: N. p., 2018. 
Web.  doi:10.1016/j.nme.2018.10.011.

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                    Abrams, T., Unterberg, E. A., McLean, A. G., Rudakov, D. L., Wampler, W. R., Knolker, M., Lasnier, C., Leonard, A. W., Stangeby, P. C., Thomas, D. M., & Wang, H. Q. Experimental validation of a model for particle recycling and tungsten erosion during ELMs in the DIII-D divertor.  Netherlands.  https://doi.org/10.1016/j.nme.2018.10.011

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                    Abrams, T., Unterberg, E. A., McLean, A. G., Rudakov, D. L., Wampler, W. R., Knolker, M., Lasnier, C., Leonard, A. W., Stangeby, P. C., Thomas, D. M., and Wang, H. Q. Sat .  
"Experimental validation of a model for particle recycling and tungsten erosion during ELMs in the DIII-D divertor".  Netherlands.  https://doi.org/10.1016/j.nme.2018.10.011.

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@article{osti_1481034,

  title        = {Experimental validation of a model for particle recycling and tungsten erosion during ELMs in the DIII-D divertor},

  author       = {Abrams, T. and Unterberg, E. A. and McLean, A. G. and Rudakov, D. L. and Wampler, W. R. and Knolker, M. and Lasnier, C. and Leonard, A. W. and Stangeby, P. C. and Thomas, D. M. and Wang, H. Q.},

  abstractNote = {A refined version of the Fundamenksi-Moulton 'free-streaming' model (FSM) for the dynamics of divertor density, particle flux, and heat flux during edge localized modes (ELMs) is presented. This model depends only on inter-ELM pedestal and divertor conditions and, crucially, incorporates particle recycling: a FSM with recycling model, FSRM. The effective particle recycling coefficient, Reff, is the only empirical fitting parameter in the FSRM. The predictions of the FSRM are systematically tested against a DIII-D database of ELM ion and energy fluence measurements and are shown to be consistent with the model across a wide range of pedestal and divertor conditions using a constant value of 0.96 for Reff. Predictions for W sputtering during ELMs are developed based on the FSRM. It is concluded that energetic free-streaming D+ ions and C6+ impurities are the dominant contributors to the intra-ELM gross erosion of W in the DIII-D divertor, i.e., recycling ions and impurities have relatively little impact on the total W sputtering rate. Furthermore, these calculations are also shown to be consistent with spectroscopic measurements of W gross erosion for three different pedestal conditions after incorporating the strong electron density dependence of the WI 400.8 nm ionizations/photon (S/XB) coefficient.},

  doi          = {10.1016/j.nme.2018.10.011},

  journal      = {Nuclear Materials and Energy},

  number       = C,

  volume       = 17,

  place        = {Netherlands},

  year         = {Sat Dec 01 00:00:00 EST 2018},

  month        = {Sat Dec 01 00:00:00 EST 2018}

}

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Works referencing / citing this record:

Impact of ELM control techniques on tungsten sputtering in the DIII-D divertor and extrapolations to ITER
journal, June 2019

Abrams, T.; Unterberg, E. A.; Rudakov, D. L.
Physics of Plasmas, Vol. 26, Issue 6
DOI: 10.1063/1.5089895

Reduced model of high-Z impurity redeposition and erosion in tokamak divertor and its application to DIII-D experiments
journal, November 2019

Guterl, J.; Wampler, W. R.; Rudakov, D.
Plasma Physics and Controlled Fusion, Vol. 61, Issue 12
DOI: 10.1088/1361-6587/ab5144

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

Petty, C. C.
Nuclear Fusion, Vol. 59, Issue 11
DOI: 10.1088/1741-4326/ab024a

Modeling of inter- and intra-edge-localized mode tungsten erosion during DIII-D H-mode discharges
journal, October 2019

Xu, G. L.; Guterl, J.; Abrams, T.
Nuclear Fusion, Vol. 59, Issue 12
DOI: 10.1088/1741-4326/ab3e96

Localized divertor leakage measurements using isotopic tungsten sources during edge-localized mode-y H-mode discharges on DIII-D
journal, November 2019

Unterberg, E. A.; Abrams, T.; Bykov, I.
Nuclear Fusion, Vol. 60, Issue 1
DOI: 10.1088/1741-4326/ab537b

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Title: Experimental validation of a model for particle recycling and tungsten erosion during ELMs in the DIII-D divertor

Abstract

Citation Formats

Impact of ELM control techniques on tungsten sputtering in the DIII-D divertor and extrapolations to ITER journal, June 2019

Reduced model of high-Z impurity redeposition and erosion in tokamak divertor and its application to DIII-D experiments journal, November 2019

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Impact of ELM control techniques on tungsten sputtering in the DIII-D divertor and extrapolations to ITER
journal, June 2019

Reduced model of high-Z impurity redeposition and erosion in tokamak divertor and its application to DIII-D experiments
journal, November 2019

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journal, June 2019

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journal, October 2019

Localized divertor leakage measurements using isotopic tungsten sources during edge-localized mode-y H-mode discharges on DIII-D
journal, November 2019