Modelling the effect of divertor closure on detachment onset in DIII-D with the SOLPS code

Casali, L.; Sang, C.; Moser, A. L.; Covele, B. M.; Guo, H. Y.; Samuell, C.

doi:10.1002/ctpp.201700215

Title: Modelling the effect of divertor closure on detachment onset in DIII-D with the SOLPS code

Journal Article · Thu Apr 26 00:00:00 EDT 2018 · Contributions to Plasma Physics

DOI:https://doi.org/10.1002/ctpp.201700215· OSTI ID:1491633

^[1]; Sang, C. ^[2]; Moser, A. L. ^[3]; Covele, B. M. ^[3]; Guo, H. Y. ^[3]; Samuell, C. ^[4]

Oak Ridge Associated Univ., Oak Ridge, TN (United States)
Dalian Univ. of Technology, Dalian (China). School of Physics
General Atomics, San Diego, CA (United States)
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

SOLPS modelling has shown that divertor plasma detachment occurs at a lower upstream separatrix density in the more closed DIII‐D upper divertor than the open lower divertor, demonstrating the utility of the divertor closure in widening the range of acceptable densities for adequate heat handling. To achieve reduced heat flux and erosion at the plasma‐facing components, future devices will need to operate in at least partially detached divertor conditions . Two‐dimensional fluid plasma models coupled to Monte Carlo neutral transport simulations, such as SOLPS, have been widely used to predict the onset of detachment. In modelling the DIII‐D discharges, the cross‐field transport coefficients are constrained to reproduce the experimental upstream profiles. The closed divertor has been modelled with the same input parameters of the open divertor, allowing a direct comparison of the target conditions in both geometries. SOLPS simulations indicate that a higher molecular density correlates strongly with lower electron temperatures. The increased closure of the upper divertor improves the trapping of neutrals, thereby reducing the power density deposited at the target and facilitating detachment, in agreement with experimental observations.

View Accepted Manuscript (DOE)

View Accepted Manuscript (Publisher)

Cite

Export

Save

Research Organization:: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

Sponsoring Organization:: USDOE National Nuclear Security Administration (NNSA)

Grant/Contract Number:: AC52-07NA27344; FC02‐04ER54698; DE‐FC02‐04ER54698; DE‐AC05‐06OR23100

OSTI ID:: 1491633

Alternate ID(s):: OSTI ID: 1434964

Report Number(s):: LLNL-JRNL-751782; 936705

Journal Information:: Contributions to Plasma Physics, Vol. 58, Issue 6-8; ISSN 0863-1042

Publisher:: WileyCopyright Statement

Country of Publication:: United States

Language:: English

Citation Metrics:

Cited by: 20 works

Citation information provided by
Web of Science

References (11)

An analytical formula and important parameters for low-energy ion sputtering Bohdansky, J.; Roth, J.; Bay, H. L. Journal of Applied Physics, Vol. 51, Issue 5 https://doi.org/10.1063/1.327954	journal	January 1980
Small angle slot divertor concept for long pulse advanced tokamaks Guo, H. Y.; Sang, C. F.; Stangeby, P. C. Nuclear Fusion, Vol. 57, Issue 4 https://doi.org/10.1088/1741-4326/aa5b46	journal	February 2017
Obtaining reactor-relevant divertor conditions in tokamaks Stangeby, P. C.; Leonard, A. W. Nuclear Fusion, Vol. 51, Issue 6 https://doi.org/10.1088/0029-5515/51/6/063001	journal	April 2011
Reconstruction of current profile parameters and plasma shapes in tokamaks Lao, L. L.; St. John, H.; Stambaugh, R. D. Nuclear Fusion, Vol. 25, Issue 11 https://doi.org/10.1088/0029-5515/25/11/007	journal	November 1985
Presentation of the New SOLPS-ITER Code Package for Tokamak Plasma Edge Modelling Bonnin, Xavier; Dekeyser, Wouter; Pitts, Richard Plasma and Fusion Research, Vol. 11, Issue 0 https://doi.org/10.1585/pfr.11.1403102	journal	January 2016
The ASDEX Upgrade divertor IIb—a closed divertor for strongly shaped plasmas Neu, R.; Fuchs, J. C.; Kallenbach, A. Nuclear Fusion, Vol. 43, Issue 10 https://doi.org/10.1088/0029-5515/43/10/021	journal	September 2003
Radiative divertor and scrape-off layer experiments in open and baffled divertors on DIII-D Allen, S. L.; Brooks, N. H.; Bastasz, R. Nuclear Fusion, Vol. 39, Issue 11Y https://doi.org/10.1088/0029-5515/39/11Y/348	journal	November 1999
Effects of divertor geometry on tokamak plasmas Loarte, Alberto Plasma Physics and Controlled Fusion, Vol. 43, Issue 6 https://doi.org/10.1088/0741-3335/43/6/201	journal	May 2001
Interpretations of the impact of cross-field drifts on divertor flows in DIII-D with UEDGE Jaervinen, A. E.; Allen, S. L.; Groth, M. Nuclear Materials and Energy, Vol. 12 https://doi.org/10.1016/j.nme.2016.11.014	journal	August 2017
Impurity seeding for tokamak power exhaust: from present devices via ITER to DEMO Kallenbach, A.; Bernert, M.; Dux, R. Plasma Physics and Controlled Fusion, Vol. 55, Issue 12 https://doi.org/10.1088/0741-3335/55/12/124041	journal	November 2013
The effect of a metal wall on confinement in JET and ASDEX Upgrade Beurskens, M. N. A.; Schweinzer, J.; Angioni, C. Plasma Physics and Controlled Fusion, Vol. 55, Issue 12 https://doi.org/10.1088/0741-3335/55/12/124043	journal	November 2013

Cited By (3)

First experimental tests of a new small angle slot divertor on DIII-D Guo, H. Y.; Wang, H. Q.; Watkins, J. G. Nuclear Fusion, Vol. 59, Issue 8 https://doi.org/10.1088/1741-4326/ab26ee	journal	July 2019
Studying divertor relevant plasmas in the Pilot-PSI linear plasma device: experiments versus modelling Ješko, K.; Marandet, Y.; Bufferand, H. Plasma Physics and Controlled Fusion, Vol. 60, Issue 12 https://doi.org/10.1088/1361-6587/aae80d	journal	November 2018
DIII-D research towards establishing the scientific basis for future fusion reactors Petty, C. C. Nuclear Fusion, Vol. 59, Issue 11 https://doi.org/10.1088/1741-4326/ab024a	journal	June 2019