Drift effects and up-down asymmetry in balanced double-null DIII-D divertor configurations

Meier, E. T.; Covele, B.; Guo, H. Y.; Thomas, D. M.

doi:10.1002/ctpp.201700167

Title: Drift effects and up-down asymmetry in balanced double-null DIII-D divertor configurations

Journal Article · Tue Jun 26 00:00:00 EDT 2018 · Contributions to Plasma Physics

DOI:https://doi.org/10.1002/ctpp.201700167· OSTI ID:1617849

^[1]; Covele, B. ^[2]; Guo, H. Y. ^[2]; Thomas, D. M. ^[2]

Univ. of Washington, Seattle, WA (United States)
General Atomics, San Diego, CA (United States)

In a preliminary design study for a small-angle slot (SAS) divertor configuration suitable for DIII-D double-null advanced tokamak (AT) plasmas, a conceptual “SAS 2” slot divertor configuration has been modelled with SOLPS-ITER. A balanced double-null equilibrium, representing an H-mode AT plasma, is employed, with 5 MW neutral beam input power. In simulations with fully recycling walls and no pumping, an up–down-symmetric open divertor geometry is compared with the SAS 2 configuration. In density scans without electric or magnetic drifts, the upstream separatrix electron density needed to achieve detachment at both target strike points (n_{e, sep, det.}) is ~35% lower in SAS 2 than in the open configuration, with n_{e, sep, det.} = 1.66 and 2.59 × 10¹⁹ m^-3, respectively. With drifts, the same ~35% difference remains, but detachment density for each configuration is shifted up by ~15%, giving n_{e, sep, det.} = 1.94 and 2.99 × 10¹⁹ m^-3, respectively. Cryopumping is modelled for the SAS 2 divertor, and with a pump duct deep in the upper slot on the common-flux side, detachment density is shifted up by ~15–20%. Strong pumping in the upper slot delays detachment there compared with the lower slot, regardless of drift direction. This research sets the stage for future modelling that would explore more sophisticated cryopumping configurations, and sensitivity of divertor performance to changes in magnetic balance and input power.

View Accepted Manuscript (DOE)

View Accepted Manuscript (Publisher)

Cite

Export

Save

Research Organization:: General Atomics, San Diego, CA (United States); College of William and Mary, Williamsburg, VA (United States)

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

Grant/Contract Number:: FC02-04ER54698; SC0007880; SC0010434

OSTI ID:: 1617849

Alternate ID(s):: OSTI ID: 1457462

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: 2 works

Citation information provided by
Web of Science

References (24)

Variation of particle exhaust with changes in divertor magnetic balance Petrie, T. W.; Allen, S. L.; Brooks, N. H. Nuclear Fusion, Vol. 46, Issue 1 https://doi.org/10.1088/0029-5515/46/1/007	journal	December 2005
Currents in the scrape-off layer of diverted tokamaks Staebler, G. M.; Hinton, F. L. Nuclear Fusion, Vol. 29, Issue 10 https://doi.org/10.1088/0029-5515/29/10/017	journal	October 1989
The scaling of the heat flux width in DIII-D Makowski, M. A.; Lasnier, C. J.; Leonard, A. W. Journal of Nuclear Materials, Vol. 438 https://doi.org/10.1016/j.jnucmat.2013.01.028	journal	July 2013
Plasma edge and plasma-wall interaction modelling: Lessons learned from metallic devices Wiesen, S.; Groth, M.; Wischmeier, M. Nuclear Materials and Energy, Vol. 12 https://doi.org/10.1016/j.nme.2017.03.033	journal	August 2017
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
High density operation for reactor-relevant power exhaust Wischmeier, M. Journal of Nuclear Materials, Vol. 463 https://doi.org/10.1016/j.jnucmat.2014.12.078	journal	August 2015
Spectroscopic measurement of atomic and molecular deuterium fluxes in the DIII-D plasma edge Hollmann, E. M.; Brezinsek, S.; Brooks, N. H. Plasma Physics and Controlled Fusion, Vol. 48, Issue 8 https://doi.org/10.1088/0741-3335/48/8/009	journal	July 2006
Divertor plasma conditions and neutral dynamics in horizontal and vertical divertor configurations in JET-ILW low confinement mode plasmas Groth, M.; Brezinsek, S.; Belo, P. Journal of Nuclear Materials, Vol. 463 https://doi.org/10.1016/j.jnucmat.2014.12.030	journal	August 2015
Analysis of drift effects on the tokamak power scrape-off width using SOLPS-ITER Meier, E. T.; Goldston, R. J.; Kaveeva, E. G. Plasma Physics and Controlled Fusion, Vol. 58, Issue 12 https://doi.org/10.1088/0741-3335/58/12/125012	journal	November 2016
SOLPS analysis of neutral baffling for the design of a new diverter in DIII-D Sang, Chaofeng; Guo, H. Y.; Stangeby, P. C. Nuclear Fusion, Vol. 57, Issue 5 https://doi.org/10.1088/1741-4326/aa6548	journal	April 2017
Analytic description of the chemical erosion of graphite by hydrogen ions Roth, J.; Garcia-Rosales, C. Nuclear Fusion, Vol. 36, Issue 12 https://doi.org/10.1088/0029-5515/36/12/I05	journal	December 1996
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
A Fusion Nuclear Science Facility for a fast-track path to DEMO Garofalo, A. M.; Abdou, M. A.; Canik, J. M. Fusion Engineering and Design, Vol. 89, Issue 7-8 https://doi.org/10.1016/j.fusengdes.2014.03.055	journal	October 2014
The Plasma Boundary of Magnetic Fusion Devices Stangeby, Peter C. Plasma Physics and Controlled Fusion, Vol. 43, Issue 2 https://doi.org/10.1887/0750305592	book	January 2000
The new SOLPS-ITER code package Wiesen, S.; Reiter, D.; Kotov, V. Journal of Nuclear Materials, Vol. 463 https://doi.org/10.1016/j.jnucmat.2014.10.012	journal	August 2015
SOLPS modeling of the effect on plasma detachment of closing the lower divertor in DIII-D Sang, C. F.; Stangeby, P. C.; Guo, H. Y. Plasma Physics and Controlled Fusion, Vol. 59, Issue 2 https://doi.org/10.1088/1361-6587/59/2/025009	journal	December 2016
The Plasma Boundary of Magnetic Fusion Devices Stangeby, P. Series in Plasma Physics https://doi.org/10.1201/9781420033328	book	January 2000
The Plasma Boundary of Magnetic Fusion Devices Ghendrih, Philippe Plasma Physics and Controlled Fusion, Vol. 43, Issue 2 https://doi.org/10.1088/0741-3335/43/2/702	journal	January 2001
Numerical modelling of high density JET divertor plasma with the SOLPS4.2 (B2-EIRENE) code Kotov, V.; Reiter, D.; Pitts, R. A. Plasma Physics and Controlled Fusion, Vol. 50, Issue 10 https://doi.org/10.1088/0741-3335/50/10/105012	journal	September 2008
Contribution of $\vec {E}\times \vec {B}$ drifts and parallel currents to divertor asymmetries Rozhansky, V.; Molchanov, P.; Veselova, I. Nuclear Fusion, Vol. 52, Issue 10 https://doi.org/10.1088/0029-5515/52/10/103017	journal	September 2012
Drifts, currents, and power scrape-off width in SOLPS-ITER modeling of DIII-D Meier, E. T.; Goldston, R. J.; Kaveeva, E. G. Nuclear Materials and Energy, Vol. 12 https://doi.org/10.1016/j.nme.2016.12.016	journal	August 2017
An investigation of the secondary-electron emission of carbon samples exposed to a hydrogen plasma Woods, M. E.; Hopkins, B. J.; Matthews, G. F. Journal of Physics D: Applied Physics, Vol. 20, Issue 9 https://doi.org/10.1088/0022-3727/20/9/008	journal	September 1987
Modeling of detachment experiments at DIII-D Canik, J. M.; Briesemeister, A. R.; Lasnier, C. J. Journal of Nuclear Materials, Vol. 463 https://doi.org/10.1016/j.jnucmat.2014.11.077	journal	August 2015
Analytic description of the chemical erosion of graphite by hydrogen ions Roth, J.; Garcia-Rosales, C. Nuclear Fusion, Vol. 37, Issue 6 https://doi.org/10.1088/0029-5515/37/6/514	journal	June 1997

Similar Records

Predictive modelling for EAST divertor operation

Journal Article · Wed Jun 15 00:00:00 EDT 2011 · Physics of Plasmas · OSTI ID:1617849

Yiping, Chen

Studies of high-{delta} (baffled) and low-{delta} (open) pumped divertor operation on DIII-D

Technical Report · Sat Aug 01 00:00:00 EDT 1998 · OSTI ID:1617849

Allen, S L; Fenstermacher, M E; Greenfield, C M

Improved core-edge compatibility using impurity seeding in the small angle slot (SAS) divertor at DIII-D

Journal Article · Tue Jun 02 00:00:00 EDT 2020 · Physics of Plasmas · OSTI ID:1617849

Casali, L.; Osborne, T. H.; Grierson, B. A.; +6 more

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
advanced tokamak
DIII-D
divertor
double-null
small-angle slot (SAS)

Title: Drift effects and up-down asymmetry in balanced double-null DIII-D divertor configurations

Citation Formats

References (24)

Similar Records

Related Subjects