On detachment asymmetry and stability
Abstract
Three issues related to the physics of divertor detachment are analyzed in detail: the criteria for the onset of complete divertor detachment, the role of neutrals in “symmetryzation” of detachment in the inner and outer divertors, and the transition to divertor detachment. The results of comprehensive 2D numerical simulations with the SOLPS4.3 package are compared with some experimental data and predictions based on simplified analytical models. It is shown that it is the ratio of the upstream plasma pressure to the specific power flux entering the recycling region that controls the local onset of detachment on a specific flux tube. P up/q reclycl≥(P up/q reclycl) crit remains the valid criterion also in the presence of seeded impurity, if the impurity radiation and hydrogen recycling regions are spatially separated. Detailed analysis indicates that the reverse plasma flow forming on the most heat loaded flux tubes in the outer divertor under the influence of the neutrals coming from the deeply detached inner divertor plays the key role in the detachment “symmetryzation” and allows the outer divertor to reach the detached regime. Finally, it is demonstrated that a gradual increase of the perpendicular heat transport in the edge plasma during transition to themore »
- Authors:
- National Research Centre (NRC), Moscow (Russian Federation). Kurchatov Inst. (NRCKI); National Research Nuclear Univ., Moscow (Russian Federation)
- National Research Nuclear Univ., Moscow (Russian Federation); Univ. of California, San Diego, CA (United States). Dept. of Physics
- Publication Date:
- Research Org.:
- Univ. of California, San Diego, CA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1535324
- Alternate Identifier(s):
- OSTI ID: 1368605
- Grant/Contract Number:
- FG02-04ER54739
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Physics of Plasmas
- Additional Journal Information:
- Journal Volume: 24; Journal Issue: 7; 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; Physics
Citation Formats
Pshenov, A. A., Kukushkin, A. S., and Krasheninnikov, S. I. On detachment asymmetry and stability. United States: N. p., 2017.
Web. doi:10.1063/1.4991402.
Pshenov, A. A., Kukushkin, A. S., & Krasheninnikov, S. I. On detachment asymmetry and stability. United States. doi:10.1063/1.4991402.
Pshenov, A. A., Kukushkin, A. S., and Krasheninnikov, S. I. Fri .
"On detachment asymmetry and stability". United States. doi:10.1063/1.4991402. https://www.osti.gov/servlets/purl/1535324.
@article{osti_1535324,
title = {On detachment asymmetry and stability},
author = {Pshenov, A. A. and Kukushkin, A. S. and Krasheninnikov, S. I.},
abstractNote = {Three issues related to the physics of divertor detachment are analyzed in detail: the criteria for the onset of complete divertor detachment, the role of neutrals in “symmetryzation” of detachment in the inner and outer divertors, and the transition to divertor detachment. The results of comprehensive 2D numerical simulations with the SOLPS4.3 package are compared with some experimental data and predictions based on simplified analytical models. It is shown that it is the ratio of the upstream plasma pressure to the specific power flux entering the recycling region that controls the local onset of detachment on a specific flux tube. Pup/qreclycl≥(Pup/qreclycl)crit remains the valid criterion also in the presence of seeded impurity, if the impurity radiation and hydrogen recycling regions are spatially separated. Detailed analysis indicates that the reverse plasma flow forming on the most heat loaded flux tubes in the outer divertor under the influence of the neutrals coming from the deeply detached inner divertor plays the key role in the detachment “symmetryzation” and allows the outer divertor to reach the detached regime. Finally, it is demonstrated that a gradual increase of the perpendicular heat transport in the edge plasma during transition to the detached regime can make this transition bifurcation-like.},
doi = {10.1063/1.4991402},
journal = {Physics of Plasmas},
number = 7,
volume = 24,
place = {United States},
year = {2017},
month = {7}
}
Web of Science
Works referenced in this record:
The role of plasma–wall interactions in thermal instabilities at the tokamak edge
journal, November 2003
- Tokar, M. Z.; Kelly, F. A.
- Physics of Plasmas, Vol. 10, Issue 11
Thermal front analysis of detached divertors and MARFEs
journal, October 1994
- Hutchinson, I. H.
- Nuclear Fusion, Vol. 34, Issue 10
Neutral recirculation—the key to control of divertor operation
journal, September 2016
- Kukushkin, A. S.; Pacher, H. D.
- Nuclear Fusion, Vol. 56, Issue 12
Steady state operation research in JT-60U with extended pulse length
journal, January 2006
- Fujita, T.; team, the JT-60
- Nuclear Fusion, Vol. 46, Issue 3
Study of near scrape-off layer (SOL) temperature and density gradient lengths with Thomson scattering
journal, November 2015
- Sun, H. J.; Wolfrum, E.; Eich, T.
- Plasma Physics and Controlled Fusion, Vol. 57, Issue 12
Plasma Recombination and Divertor Detachment
journal, January 1996
- Krasheninnikov, S. I.; Pigarov, A. Yu.; Sigmar, D. J.
- Contributions to Plasma Physics, Vol. 36, Issue 2-3
Plasma detachment in JET Mark I divertor experiments
journal, March 1998
- Loarte, A.; Monk, R. D.; Martín-Solís, J. R.
- Nuclear Fusion, Vol. 38, Issue 3
Divertor plasma detachment
journal, May 2016
- Krasheninnikov, S. I.; Kukushkin, A. S.; Pshenov, A. A.
- Physics of Plasmas, Vol. 23, Issue 5
Electron pressure balance in the SOL through the transition to detachment
journal, August 2015
- McLean, A. G.; Leonard, A. W.; Makowski, M. A.
- Journal of Nuclear Materials, Vol. 463
Stability of the detachment front in a tokamak divertor
journal, March 1999
- Krasheninnikov, S. I.; Rensink, M.; Rognlien, T. D.
- Journal of Nuclear Materials, Vol. 266-269
Plasma detachment from divertor targets and limiters
journal, April 1995
- Matthews, G. F.
- Journal of Nuclear Materials, Vol. 220-222
Study of recombining gas targets
journal, February 1997
- Borrass, K.; Coster, D.; Reiter, D.
- Journal of Nuclear Materials, Vol. 241-243
Partial detachment of high power discharges in ASDEX Upgrade
journal, April 2015
- Kallenbach, A.; Bernert, M.; Beurskens, M.
- Nuclear Fusion, Vol. 55, Issue 5
Divertor modelling and extrapolation to reactor conditions
journal, May 2002
- Kukushkin, A. S.; Pacher, H. D.
- Plasma Physics and Controlled Fusion, Vol. 44, Issue 6
Can detached divertor plasmas be explained as self-sustained gas targets?
journal, November 1993
- Stangeby, P. C.
- Nuclear Fusion, Vol. 33, Issue 11
A new experimental classification of divertor detachment in ASDEX Upgrade
journal, November 2013
- Potzel, S.; Wischmeier, M.; Bernert, M.
- Nuclear Fusion, Vol. 54, Issue 1
Role of divertor geometry on detachment and core plasma performance in JT60U
journal, March 1999
- Asakura, N.; Hosogane, N.; Itami, K.
- Journal of Nuclear Materials, Vol. 266-269
Control of particle and energy transport across the boundary of a Tokamak plasma
journal, January 1984
- Lackner, K.; Chodura, R.; Kaufmann, M.
- Plasma Physics and Controlled Fusion, Vol. 26, Issue 1A
Finalizing the ITER divertor design: The key role of SOLPS modeling
journal, December 2011
- Kukushkin, A. S.; Pacher, H. D.; Kotov, V.
- Fusion Engineering and Design, Vol. 86, Issue 12
Self-sustained oscillations in the divertor plasma
journal, November 1987
- Krasheninnikov, S. I.; Kukushkin, A. S.; Pistunovich, V. I.
- Nuclear Fusion, Vol. 27, Issue 11
Influence of atomic physics on EDGE2D-EIRENE simulations of JET divertor detachment with carbon and beryllium/tungsten plasma-facing components
journal, August 2014
- Guillemaut, C.; Pitts, R. A.; Kukushkin, A. S.
- Nuclear Fusion, Vol. 54, Issue 9
Two-dimensional effects in plasma radiation fronts and radiation front jumps in tokamak divertor plasmas
journal, November 1997
- Krasheninnikov, S. I.
- Physics of Plasmas, Vol. 4, Issue 11
Toroidal field reversal effects on divertor asymmetries in JET
journal, September 1996
- Chankin, A. V.; Campbell, D. J.; Clement, S.
- Plasma Physics and Controlled Fusion, Vol. 38, Issue 9