2D analysis of tokamak divertor-plasma detachment-bifurcation with operational parameters and geometries

Zhao, M.; Scotti, F.; Rognlien, T. D.; McLean, A. G.; Burke, G.; Holm, A.

doi:10.1016/j.nme.2024.101811

2D analysis of tokamak divertor-plasma detachment-bifurcation with operational parameters and geometries

Journal Article · Tue Nov 26 00:00:00 EST 2024 · Nuclear Materials and Energy

DOI:https://doi.org/10.1016/j.nme.2024.101811· OSTI ID:2478998

^[1]; Scotti, F. ^[1]; Rognlien, T. D. ^[1]; McLean, A. G. ^[1]; ^[1]; ^[1]

Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

UEDGE simulations with density scans for various input power, transport coefficients and outer poloidal leg length are performed to study the conditions for the existence of a bifurcation-like drop of T_e at the outer strike point, commonly referred to as a detachment cliff, when transitioning to a detached plasma from an attached plasma in the outer divertor as the upstream density increases (McLean et al., 2015). The simulation results show that a detachment cliff tends to occur with a higher power input regardless of diffusivities and leg length. Further analysis of change of plasma profiles at a cliff indicate that, in addition to the sharp reduction of the E x B drift fluxes in the outer divertor studied in Jaervinen et al., (2018), the substantial change of the Mach number in the outer divertor and the decrease of the outer mid-plane T_e due to the radiation front moving across the separatrix into the confinement region above the X-point consistently occur for all UEDGE density scans that have a detachment cliff. UEDGE time-dependent simulation of the evolution of a detachment cliff shows that the rapid increase of radiation above the X-point occurs in a time scale of ~0.3–0.5, which could possibly be the trigger for the formation of a detachment cliff, quicker than the Mach number change in a time scale of ~1 ms and the drop of T_e in a time scale of ~2–3 ms in the outer divertor.

View Journal Article

Research Organization:: General Atomics, San Diego, CA (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF); USDOE Office of Science (SC), Fusion Energy Sciences (FES)

Grant/Contract Number:: AC52-07NA27344; FC02-04ER54698

OSTI ID:: 2478998

Alternate ID(s):: OSTI ID: 2479020
OSTI ID: 2510862

Journal Information:: Nuclear Materials and Energy, Journal Name: Nuclear Materials and Energy Vol. 41; ISSN 2352-1791

Publisher:: ElsevierCopyright Statement

Country of Publication:: United States

Language:: English

References (18)

The Particle and Heat Drift Fluxes and their Implementation into the EDGE2D Transport Code Radford, G. J.; Chankin, A. V.; Corrigan, G. Contributions to Plasma Physics, Vol. 36, Issue 2-3 https://doi.org/10.1002/ctpp.2150360217	journal	January 1996
A fully implicit, time dependent 2-D fluid code for modeling tokamak edge plasmas Rognlien, T. D.; Milovich, J. L.; Rensink, M. E. Journal of Nuclear Materials, Vol. 196-198 https://doi.org/10.1016/S0022-3115(06)80058-9	journal	December 1992
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
Electron pressure balance in the SOL through the transition to detachment McLean, A. G.; Leonard, A. W.; Makowski, M. A. Journal of Nuclear Materials, Vol. 463 https://doi.org/10.1016/j.jnucmat.2015.01.066	journal	August 2015
Comparison of 2D simulations of detached divertor plasmas with divertor Thomson measurements in the DIII-D tokamak Rognlien, T. D.; McLean, A. G.; Fenstermacher, M. E. Nuclear Materials and Energy, Vol. 12 https://doi.org/10.1016/j.nme.2016.12.002	journal	August 2017
Physics of ultimate detachment of a tokamak divertor plasma Krasheninnikov, S. I.; Kukushkin, A. S. Journal of Plasma Physics, Vol. 83, Issue 5 https://doi.org/10.1017/S0022377817000654	journal	September 2017
Data-driven model for divertor plasma detachment prediction Zhu, Ben; Zhao, Menglong; Bhatia, Harsh Journal of Plasma Physics, Vol. 88, Issue 5 https://doi.org/10.1017/S002237782200085X	journal	October 2022
Flow reversal, convection, and modeling in the DIII-D divertor Boedo, J. A.; Porter, G. D.; Schaffer, M. J. Physics of Plasmas, Vol. 5, Issue 12 https://doi.org/10.1063/1.873168	journal	December 1998
Numerical modelling for divertor design of the WEST device with a focus on plasma–wall interactions Bufferand, H.; Ciraolo, G.; Marandet, Y. Nuclear Fusion, Vol. 55, Issue 5 https://doi.org/10.1088/0029-5515/55/5/053025	journal	April 2015
Basic physical processes and reduced models for plasma detachment Stangeby, P. C. Plasma Physics and Controlled Fusion, Vol. 60, Issue 4 https://doi.org/10.1088/1361-6587/aaacf6	journal	March 2018
Existence of a detachment cliff at ASDEX Upgrade Scotti, L.; Cavedon, M.; Bernert, M. Plasma Physics and Controlled Fusion, Vol. 66, Issue 7 https://doi.org/10.1088/1361-6587/ad481d	journal	May 2024
Controlling marginally detached divertor plasmas Eldon, D.; Kolemen, E.; Barton, J. L. Nuclear Fusion, Vol. 57, Issue 6 https://doi.org/10.1088/1741-4326/aa6b16	journal	May 2017
SOLPS analysis of the necessary conditions for detachment cliff Du, Hailong; Zheng, Guoyao; Guo, Houyang Nuclear Fusion, Vol. 60, Issue 4 https://doi.org/10.1088/1741-4326/ab77e6	journal	March 2020
E × B flow driven electron temperature bifurcation in a closed slot divertor with ion B × ∇B away from the X-point in the DIII-D tokamak Ma, X.; Wang, H. Q.; Guo, H. Y. Nuclear Fusion, Vol. 62, Issue 12 https://doi.org/10.1088/1741-4326/ac9743	journal	October 2022
Bifurcation-like transition of divertor conditions induced by X-point radiation in KSTAR L-mode plasmas ^* Park, Jae-Sun; Pitts, Richard; Jang, Juhyeok Nuclear Fusion, Vol. 63, Issue 8 https://doi.org/10.1088/1741-4326/acdefe	journal	June 2023
E × B Flux Driven Detachment Bifurcation in the DIII-D Tokamak Jaervinen, A. E.; Allen, S. L.; Eldon, D. Physical Review Letters, Vol. 121, Issue 7 https://doi.org/10.1103/PhysRevLett.121.075001	journal	August 2018
Development of Integrated SOL/Divertor Code and Simulation Study in JAEA Kawashima, Hisato; Shimizu, Katsuhiro; Takizuka, Tomonori Plasma and Fusion Research, Vol. 1 https://doi.org/10.1585/pfr.1.031	journal	January 2006
Global particle buildup simulations with gas puff scan: application to WEST discharge Kudashev, I.; Scotto d’Abusco, M.; Glasser, A. Frontiers in Physics, Vol. 12 https://doi.org/10.3389/fphy.2024.1407534	journal	August 2024

Similar Records

SOLPS analysis of the necessary conditions for detachment cliff

Journal Article · Sun Mar 15 20:00:00 EDT 2020 · Nuclear Fusion · OSTI ID:1608953

Comparison of 2D simulations of detached divertor plasmas with divertor Thomson measurements in the DIII-D tokamak

Journal Article · Thu Jan 26 19:00:00 EST 2017 · Nuclear Materials and Energy · OSTI ID:1372467

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
Detachment bifurcation
Scrape-off layer
Supersonic flows
UEDGE

2D analysis of tokamak divertor-plasma detachment-bifurcation with operational parameters and geometries

Citation Formats

References (18)

Similar Records

Related Subjects