Simulations of divertor plasmas with inverse sheaths
Abstract
The effect of strong electron emission from material surfaces has been proposed to form an “inverse sheath”: a region with a positive potential relative to the near-wall plasma which prevents the flow of ions to the wall [M. D. Campanell, “Negative plasma potential relative to electronemitting surfaces,” Phys. Rev. E. 88, 033103 (2013); M. D. Campanell and M. V. Umansky, “Strongly emitting surfaces unable to float below plasma potential,” Phys. Rev. Lett. 116, 1–5 (2016); M. D. Campanell and G. R. Johnson, “Thermionic cooling of the target plasma to a sub-ev temperature,” Phys. Rev. Lett. 122, 1–5 (2019)]. We assess the viability of this regime in a tokamak device using the 2D edge plasma transport code UEDGE [T. Rognlien et al., “A fully implicit, time dependent 2-D fluid code for modeling tokamak edge plasmas,” J. Nucl. Mater. 196–198, 347–351 (1992)]. Since the UEDGE code does not consider the sheath region directly, we apply boundary conditions at the divertor targets which emulate the physics of both “standard” and “inverse” sheath regimes [R. Masline et al., “Influence of the inverse sheath on divertor plasma performance in tokamak edge plasma simulations,” Contrib. Plasma Phys. 60, e201900097 (2020)]. Using these boundary conditions, we performmore »
- Publication Date:
- Research Org.:
- Univ. of California, San Diego, CA (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1800219
- Alternate Identifier(s):
- OSTI ID: 1658642
- Grant/Contract Number:
- FG02-04ER54739
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Physics of Plasmas
- Additional Journal Information:
- Journal Volume: 27; Journal Issue: 9; 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; Plasma material interactions; Tokamaks; Plasma sheaths; Fusion reactors
Citation Formats
Masline, R., Smirnov, R. D., and Krasheninnikov, S. I. Simulations of divertor plasmas with inverse sheaths. United States: N. p., 2020.
Web. doi:10.1063/5.0015995.
Masline, R., Smirnov, R. D., & Krasheninnikov, S. I. Simulations of divertor plasmas with inverse sheaths. United States. https://doi.org/10.1063/5.0015995
Masline, R., Smirnov, R. D., and Krasheninnikov, S. I. Tue .
"Simulations of divertor plasmas with inverse sheaths". United States. https://doi.org/10.1063/5.0015995. https://www.osti.gov/servlets/purl/1800219.
@article{osti_1800219,
title = {Simulations of divertor plasmas with inverse sheaths},
author = {Masline, R. and Smirnov, R. D. and Krasheninnikov, S. I.},
abstractNote = {The effect of strong electron emission from material surfaces has been proposed to form an “inverse sheath”: a region with a positive potential relative to the near-wall plasma which prevents the flow of ions to the wall [M. D. Campanell, “Negative plasma potential relative to electronemitting surfaces,” Phys. Rev. E. 88, 033103 (2013); M. D. Campanell and M. V. Umansky, “Strongly emitting surfaces unable to float below plasma potential,” Phys. Rev. Lett. 116, 1–5 (2016); M. D. Campanell and G. R. Johnson, “Thermionic cooling of the target plasma to a sub-ev temperature,” Phys. Rev. Lett. 122, 1–5 (2019)]. We assess the viability of this regime in a tokamak device using the 2D edge plasma transport code UEDGE [T. Rognlien et al., “A fully implicit, time dependent 2-D fluid code for modeling tokamak edge plasmas,” J. Nucl. Mater. 196–198, 347–351 (1992)]. Since the UEDGE code does not consider the sheath region directly, we apply boundary conditions at the divertor targets which emulate the physics of both “standard” and “inverse” sheath regimes [R. Masline et al., “Influence of the inverse sheath on divertor plasma performance in tokamak edge plasma simulations,” Contrib. Plasma Phys. 60, e201900097 (2020)]. Using these boundary conditions, we perform scoping studies to assess plasma parameters near the target by varying the density at the core-edge interface. We observe a smooth transition in the resultant profiles of plasma parameters for the standard sheath, and a bifurcation across the simulation set for plasmas with an inverse sheath. The cause of this bifurcation is assessed by performing the parameter scan both with and without impurity radiation; we observe that the bifurcation persists in both cases, indicating that this bifurcation is caused by plasma recombination.},
doi = {10.1063/5.0015995},
journal = {Physics of Plasmas},
number = 9,
volume = 27,
place = {United States},
year = {Tue Sep 08 00:00:00 EDT 2020},
month = {Tue Sep 08 00:00:00 EDT 2020}
}
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Works referenced in this record:
Thermionic Cooling of the Target Plasma to a Sub-eV Temperature
journal, January 2019
- Campanell, M. D.; Johnson, G. R.
- Physical Review Letters, Vol. 122, Issue 1
Strongly Emitting Surfaces Unable to Float below Plasma Potential
journal, February 2016
- Campanell, M. D.; Umansky, M. V.
- Physical Review Letters, Vol. 116, Issue 8
Negative plasma potential relative to electron-emitting surfaces
journal, September 2013
- Campanell, M. D.
- Physical Review E, Vol. 88, Issue 3
Heat flow through a Langmuir sheath in the presence of electron emission
journal, January 1967
- Hobbs, G. D.; Wesson, J. A.
- Plasma Physics, Vol. 9, Issue 1
Influence of the inverse sheath on divertor plasma performance in tokamak edge plasma simulations
journal, December 2019
- Masline, Rebecca; Smirnov, Roman D.; Krasheninnikov, Sergei I.
- Contributions to Plasma Physics
Review of MARFE phenomena in tokamaks
journal, February 1987
- Lipschultz, B.
- Journal of Nuclear Materials, Vol. 145-147
The Plasma Boundary of Magnetic Fusion Devices
book, January 2000
- Stangeby, Peter C.
- Plasma Physics and Controlled Fusion, Vol. 43, Issue 2
Physics of ultimate detachment of a tokamak divertor plasma
journal, September 2017
- Krasheninnikov, S. I.; Kukushkin, A. S.
- Journal of Plasma Physics, Vol. 83, Issue 5
Flux Driven Detachment Bifurcation in the DIII-D Tokamak
journal, August 2018
- Jaervinen, A. E.; Allen, S. L.; Eldon, D.
- Physical Review Letters, Vol. 121, Issue 7
A fully implicit, time dependent 2-D fluid code for modeling tokamak edge plasmas
journal, December 1992
- Rognlien, T. D.; Milovich, J. L.; Rensink, M. E.
- Journal of Nuclear Materials, Vol. 196-198
Stability of divertor detachment
journal, August 2017
- Krasheninnikov, S. I.; Kukushkin, A. S.; Pshenov, A. A.
- Nuclear Materials and Energy, Vol. 12
On thermionic emission from plasma-facing components in tokamak-relevant conditions
journal, July 2017
- Komm, M.; Ratynskaia, S.; Tolias, P.
- Plasma Physics and Controlled Fusion, Vol. 59, Issue 9
Plasma-material interactions in current tokamaks and their implications for next step fusion reactors
journal, December 2001
- Federici, G.; Skinner, C. H.; Brooks, J. N.
- Nuclear Fusion, Vol. 41, Issue 12