Effects of two-dimensional magnetic uncertainties and three-dimensional error and perturbation fields on the Small Angle Slot divertor geometry and topology [Effects of two- and three-dimensional magnetic fields on the Small Angle Slot divertor magnetic topology]
Abstract
The Small Angle Slot (SAS) was recently installed on DIII-D as an advanced divertor, promising easier plasma detachment and lower temperatures across the whole target. A twofold study of the SAS magnetic geometry and topology is presented in this paper. On one hand, a two-dimensional uncertainty quantification analysis is carried out through a Monte Carlo approach in order to understand the level of accuracy of two-dimensional equilibrium computations in reconstructing the strike point and angle onto the divertor. Under typical experimental conditions, the uncertainties are found to be roughly 6.8 mm and 0.56 deg, respectively. On the other hand, a three-dimensional 'vacuum' analysis is carried out to understand the effects of typical external perturbation fields on the scrape-off layer topology. When the non-axisymmetric I-coils are switched on, poloidally-localized lobes are found to appear, grow, and hit the SAS target, although barely, even for 5 kA; at the same time, the strike point modulation is found to be roughly 1.8 mm and thus negligible for most purposes. Such results complement previous two-dimensional analyses in characterizing typical SAS equilibria and provide useful background information for planning and interpreting SAS experiments.
- Authors:
-
[1];
- Oak Ridge Associated Univ., Oak Ridge, TN (United States); General Atomics, San Diego, CA (United States)
- General Atomics, San Diego, CA (United States)
- Univ. of California-San Diego, San Diego, CA (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Publication Date:
- Research Org.:
- General Atomics, San Diego, CA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- USDOE Office of Nuclear Energy (NE)
- OSTI Identifier:
- 1415991
- Alternate Identifier(s):
- OSTI ID: 1422607
- Grant/Contract Number:
- FC02-04ER54698; AC05-00OR22725
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Nuclear Fusion
- Additional Journal Information:
- Journal Volume: 58; Journal Issue: 2; Journal ID: ISSN 0029-5515
- Publisher:
- IOP Science
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; plasma physics; DIII-D; magnetic topology; divertor footprint
Citation Formats
Trevisan, Gregorio L., Lao, Lang L., Evans, Todd E., Guo, Hou Yang, Orlov, Dmitry M., Strait, Edward J., Wingen, Andreas, and Wu, Wen. Effects of two-dimensional magnetic uncertainties and three-dimensional error and perturbation fields on the Small Angle Slot divertor geometry and topology [Effects of two- and three-dimensional magnetic fields on the Small Angle Slot divertor magnetic topology]. United States: N. p., 2018.
Web. doi:10.1088/1741-4326/aa9dab.
Trevisan, Gregorio L., Lao, Lang L., Evans, Todd E., Guo, Hou Yang, Orlov, Dmitry M., Strait, Edward J., Wingen, Andreas, & Wu, Wen. Effects of two-dimensional magnetic uncertainties and three-dimensional error and perturbation fields on the Small Angle Slot divertor geometry and topology [Effects of two- and three-dimensional magnetic fields on the Small Angle Slot divertor magnetic topology]. United States. https://doi.org/10.1088/1741-4326/aa9dab
Trevisan, Gregorio L., Lao, Lang L., Evans, Todd E., Guo, Hou Yang, Orlov, Dmitry M., Strait, Edward J., Wingen, Andreas, and Wu, Wen. Thu .
"Effects of two-dimensional magnetic uncertainties and three-dimensional error and perturbation fields on the Small Angle Slot divertor geometry and topology [Effects of two- and three-dimensional magnetic fields on the Small Angle Slot divertor magnetic topology]". United States. https://doi.org/10.1088/1741-4326/aa9dab. https://www.osti.gov/servlets/purl/1415991.
@article{osti_1415991,
title = {Effects of two-dimensional magnetic uncertainties and three-dimensional error and perturbation fields on the Small Angle Slot divertor geometry and topology [Effects of two- and three-dimensional magnetic fields on the Small Angle Slot divertor magnetic topology]},
author = {Trevisan, Gregorio L. and Lao, Lang L. and Evans, Todd E. and Guo, Hou Yang and Orlov, Dmitry M. and Strait, Edward J. and Wingen, Andreas and Wu, Wen},
abstractNote = {The Small Angle Slot (SAS) was recently installed on DIII-D as an advanced divertor, promising easier plasma detachment and lower temperatures across the whole target. A twofold study of the SAS magnetic geometry and topology is presented in this paper. On one hand, a two-dimensional uncertainty quantification analysis is carried out through a Monte Carlo approach in order to understand the level of accuracy of two-dimensional equilibrium computations in reconstructing the strike point and angle onto the divertor. Under typical experimental conditions, the uncertainties are found to be roughly 6.8 mm and 0.56 deg, respectively. On the other hand, a three-dimensional 'vacuum' analysis is carried out to understand the effects of typical external perturbation fields on the scrape-off layer topology. When the non-axisymmetric I-coils are switched on, poloidally-localized lobes are found to appear, grow, and hit the SAS target, although barely, even for 5 kA; at the same time, the strike point modulation is found to be roughly 1.8 mm and thus negligible for most purposes. Such results complement previous two-dimensional analyses in characterizing typical SAS equilibria and provide useful background information for planning and interpreting SAS experiments.},
doi = {10.1088/1741-4326/aa9dab},
journal = {Nuclear Fusion},
number = 2,
volume = 58,
place = {United States},
year = {Thu Jan 04 00:00:00 EST 2018},
month = {Thu Jan 04 00:00:00 EST 2018}
}
Free Publicly Available Full Text
Publisher's Version of Record
Other availability
Search WorldCat to find libraries that may hold this journal
Cited by: 1 work
Citation information provided by
Web of Science
Web of Science
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.
Works referenced in this record:
Error field mode studies on JET, COMPASS-D and DIII-D, and implications for ITER
journal, November 1999
- Buttery, R. J.; Benedetti, M. De'; Gates, D. A.
- Nuclear Fusion, Vol. 39, Issue 11Y
Modeling of stochastic magnetic flux loss from the edge of a poloidally diverted tokamak
journal, December 2002
- Evans, T. E.; Moyer, R. A.; Monat, P.
- Physics of Plasmas, Vol. 9, Issue 12
Edge stability and transport control with resonant magnetic perturbations in collisionless tokamak plasmas
journal, May 2006
- Evans, Todd E.; Moyer, Richard A.; Burrell, Keith H.
- Nature Physics, Vol. 2, Issue 6
Experimental signatures of homoclinic tangles in poloidally diverted tokamaks
journal, January 2005
- Evans, T. E.; Roeder, R. K. W.; Carter, J. A.
- Journal of Physics: Conference Series, Vol. 7
Experimental and numerical studies of separatrix splitting and magnetic footprints in DIII-D
journal, June 2007
- Evans, T. E.; Joseph, I.; Moyer, R. A.
- Journal of Nuclear Materials, Vol. 363-365
Real time equilibrium reconstruction for tokamak discharge control
journal, July 1998
- Ferron, J. R.; Walker, M. L.; Lao, L. L.
- Nuclear Fusion, Vol. 38, Issue 7
MAST-upgrade divertor facility and assessing performance of long-legged divertors
journal, July 2013
- Fishpool, G.; Canik, J.; Cunningham, G.
- Journal of Nuclear Materials, Vol. 438
Accelerating the numerical simulation of magnetic field lines in tokamaks using the GPU
journal, June 2011
- Kalling, R. C.; Evans, T. E.; Orlov, D. M.
- Fusion Engineering and Design, Vol. 86, Issue 4-5
Separation of β̄ p and ℓ i in tokamaks of non-circular cross-section
journal, October 1985
- Lao, L. L.; John, H. St.; Stambaugh, R. D.
- Nuclear Fusion, Vol. 25, Issue 10
Reconstruction of current profile parameters and plasma shapes in tokamaks
journal, November 1985
- Lao, L. L.; St. John, H.; Stambaugh, R. D.
- Nuclear Fusion, Vol. 25, Issue 11
Proposal of an alternative upper divertor in ASDEX Upgrade supported by EMC3-EIRENE simulations
journal, August 2017
- Lunt, T.; Zohm, H.; Herrmann, A.
- Nuclear Materials and Energy, Vol. 12
A design retrospective of the DIII-D tokamak
journal, May 2002
- Luxon, J. L.
- Nuclear Fusion, Vol. 42, Issue 5
Anomalies in the applied magnetic fields in DIII-D and their implications for the understanding of stability experiments
journal, December 2003
- Luxon, J. L.; Schaffer, M. J.; Jackson, G. L.
- Nuclear Fusion, Vol. 43, Issue 12
Integrated modeling applications for tokamak experiments with OMFIT
journal, July 2015
- Meneghini, O.; Smith, S. P.; Lao, L. L.
- Nuclear Fusion, Vol. 55, Issue 8
Dynamic diagnostics of the error fields in tokamaks
journal, June 2007
- Pustovitov, V. D.
- Nuclear Fusion, Vol. 47, Issue 7
TCV divertor upgrade for alternative magnetic configurations
journal, August 2017
- Reimerdes, H.; Alberti, S.; Blanchard, P.
- Nuclear Materials and Energy, Vol. 12
Measurement of resistive wall mode stability in rotating high-β DIII-D plasmas
journal, April 2005
- Reimerdes, H.; Bialek, J.; Chance, M. S.
- Nuclear Fusion, Vol. 45, Issue 5
Advances in global MHD mode stabilization research on NSTX
journal, January 2010
- Sabbagh, S. A.; Berkery, J. W.; Bell, R. E.
- Nuclear Fusion, Vol. 50, Issue 2
Strong correlation between D 2 density and electron temperature at the target of divertors found in SOLPS analysis
journal, March 2017
- Stangeby, P. C.; Sang, Chaofeng
- Nuclear Fusion, Vol. 57, Issue 5
Magnetic diagnostic system of the DIII-D tokamak
journal, February 2006
- Strait, E. J.
- Review of Scientific Instruments, Vol. 77, Issue 2
Footprint structures due to resonant magnetic perturbations in DIII-D
journal, April 2009
- Wingen, A.; Evans, T. E.; Spatschek, K. H.
- Physics of Plasmas, Vol. 16, Issue 4
Nonaxisymmetric field effects on Alcator C-Mod
journal, May 2005
- Wolfe, S. M.; Hutchinson, I. H.; Granetz, R. S.
- Physics of Plasmas, Vol. 12, Issue 5
Works referencing / citing this record:
Assessment of equilibrium field coil misalignments on the divertor footprints in NSTX-U
journal, June 2019
- Munaretto, S.; Evans, T. E.; Ferraro, N. M.
- Nuclear Fusion, Vol. 59, Issue 7