Non-local heat transport, rotation reversals and up/down impurity density asymmetries in Alcator C-Mod ohmic L-mode plasmas
Several seemingly unrelated effects in Alcator C-Mod ohmic L-mode plasmas are shown to be closely connected: non-local heat transport, core toroidal rotation reversals, energy confinement saturation and up/down impurity density asymmetries. These phenomena all abruptly transform at a critical value...
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
IOP Publishing
2013
|
| Online Access: | http://hdl.handle.net/1721.1/81463 https://orcid.org/0000-0003-3234-8733 https://orcid.org/0000-0001-8319-5971 https://orcid.org/0000-0002-9518-4097 https://orcid.org/0000-0002-9604-204X https://orcid.org/0000-0003-2951-9749 https://orcid.org/0000-0002-4438-729X https://orcid.org/0000-0002-5283-0546 https://orcid.org/0000-0002-3616-8484 https://orcid.org/0000-0002-0026-6939 |
| _version_ | 1826213915463254016 |
|---|---|
| author | Diamond, P. H. Sun, H. J. Cziegler, Istvan Podpaly, Y. A. Rowan, W. L. Delgado-Aparicio, Luis Ma, Y. Marmar, E. S. Rice, John E. Reinke, Matthew Logan Howard, Nathaniel Thomas Hubbard, Amanda E. Terry, James L. Chilenski, Mark Alan Ennever, Paul Chappell Ernst, Darin R. Greenwald, Martin J. Hughes, Jerry W. Marmar, Earl S. Porkolab, Miklos White, Anne E. Wolfe, Stephen M. Gao, Chi, Ph. D. Massachusetts Institute of Technology |
| author2 | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Diamond, P. H. Sun, H. J. Cziegler, Istvan Podpaly, Y. A. Rowan, W. L. Delgado-Aparicio, Luis Ma, Y. Marmar, E. S. Rice, John E. Reinke, Matthew Logan Howard, Nathaniel Thomas Hubbard, Amanda E. Terry, James L. Chilenski, Mark Alan Ennever, Paul Chappell Ernst, Darin R. Greenwald, Martin J. Hughes, Jerry W. Marmar, Earl S. Porkolab, Miklos White, Anne E. Wolfe, Stephen M. Gao, Chi, Ph. D. Massachusetts Institute of Technology |
| author_sort | Diamond, P. H. |
| collection | MIT |
| description | Several seemingly unrelated effects in Alcator C-Mod ohmic L-mode plasmas are shown to be closely connected: non-local heat transport, core toroidal rotation reversals, energy confinement saturation and up/down impurity density asymmetries. These phenomena all abruptly transform at a critical value of the collisionality. At low densities in the linear ohmic confinement regime, with collisionality ν[subscript *] ≤ 0.35 (evaluated inside of the q = 3/2 surface), heat transport exhibits non-local behaviour, core toroidal rotation is directed co-current, edge impurity density profiles are up/down symmetric and a turbulent feature in core density fluctuations with k[subscript θ] up to 15 cm[superscript −1] (k[subscript θ]ρ[subscript s] ~ 1) is present. At high density/collisionality with saturated ohmic confinement, electron thermal transport is diffusive, core rotation is in the counter-current direction, edge impurity density profiles are up/down asymmetric and the high k[subscript θ] turbulent feature is absent. The rotation reversal stagnation point (just inside of the q = 3/2 surface) coincides with the non-local electron temperature profile inversion radius. All of these observations suggest a possible unification in a model with trapped electron mode prevalence at low collisionality and ion temperature gradient mode domination at high collisionality. |
| first_indexed | 2024-09-23T15:56:53Z |
| format | Article |
| id | mit-1721.1/81463 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:56:53Z |
| publishDate | 2013 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/814632023-02-26T02:09:19Z Non-local heat transport, rotation reversals and up/down impurity density asymmetries in Alcator C-Mod ohmic L-mode plasmas Diamond, P. H. Sun, H. J. Cziegler, Istvan Podpaly, Y. A. Rowan, W. L. Delgado-Aparicio, Luis Ma, Y. Marmar, E. S. Rice, John E. Reinke, Matthew Logan Howard, Nathaniel Thomas Hubbard, Amanda E. Terry, James L. Chilenski, Mark Alan Ennever, Paul Chappell Ernst, Darin R. Greenwald, Martin J. Hughes, Jerry W. Marmar, Earl S. Porkolab, Miklos White, Anne E. Wolfe, Stephen M. Gao, Chi, Ph. D. Massachusetts Institute of Technology Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Massachusetts Institute of Technology. Department of Physics Massachusetts Institute of Technology. Plasma Science and Fusion Center Rice, John E. Gao, Chi Reinke, Matthew Logan Howard, Nathaniel Thomas Hubbard, Amanda E. Podpaly, Y.A. Terry, James L. Chilenski, Mark Alan Ennever, Paul Chappell Ernst, Darin R. Greenwald, Martin J. Hughes, Jerry W. Ma, Y. Marmar, Earl S. Porkolab, Miklos White, Anne E. Wolfe, Stephen M. Several seemingly unrelated effects in Alcator C-Mod ohmic L-mode plasmas are shown to be closely connected: non-local heat transport, core toroidal rotation reversals, energy confinement saturation and up/down impurity density asymmetries. These phenomena all abruptly transform at a critical value of the collisionality. At low densities in the linear ohmic confinement regime, with collisionality ν[subscript *] ≤ 0.35 (evaluated inside of the q = 3/2 surface), heat transport exhibits non-local behaviour, core toroidal rotation is directed co-current, edge impurity density profiles are up/down symmetric and a turbulent feature in core density fluctuations with k[subscript θ] up to 15 cm[superscript −1] (k[subscript θ]ρ[subscript s] ~ 1) is present. At high density/collisionality with saturated ohmic confinement, electron thermal transport is diffusive, core rotation is in the counter-current direction, edge impurity density profiles are up/down asymmetric and the high k[subscript θ] turbulent feature is absent. The rotation reversal stagnation point (just inside of the q = 3/2 surface) coincides with the non-local electron temperature profile inversion radius. All of these observations suggest a possible unification in a model with trapped electron mode prevalence at low collisionality and ion temperature gradient mode domination at high collisionality. United States. Dept. of Energy (Contract DE-FC02-99ER54512) United States. Dept. of Energy. Office of Fusion Energy Sciences (Postdoctoral Research Program) 2013-10-21T18:07:21Z 2013-10-21T18:07:21Z 2013-02 2012-08 Article http://purl.org/eprint/type/JournalArticle 0029-5515 1741-4326 http://hdl.handle.net/1721.1/81463 Rice, J.E., C. Gao, M.L. Reinke, P.H. Diamond, N.T. Howard, H.J. Sun, I. Cziegler, et al. “Non-local heat transport, rotation reversals and up/down impurity density asymmetries in Alcator C-Mod ohmic L-mode plasmas.” Nuclear Fusion 53, no. 3 (March 1, 2013): 033004. https://orcid.org/0000-0003-3234-8733 https://orcid.org/0000-0001-8319-5971 https://orcid.org/0000-0002-9518-4097 https://orcid.org/0000-0002-9604-204X https://orcid.org/0000-0003-2951-9749 https://orcid.org/0000-0002-4438-729X https://orcid.org/0000-0002-5283-0546 https://orcid.org/0000-0002-3616-8484 https://orcid.org/0000-0002-0026-6939 en_US http://dx.doi.org/10.1088/0029-5515/53/3/033004 Nuclear Fusion Creative Commons Attribution-Noncommercial-Share Alike 3.0 http://creativecommons.org/licenses/by-nc-sa/3.0/ application/pdf IOP Publishing MIT Web Domain |
| spellingShingle | Diamond, P. H. Sun, H. J. Cziegler, Istvan Podpaly, Y. A. Rowan, W. L. Delgado-Aparicio, Luis Ma, Y. Marmar, E. S. Rice, John E. Reinke, Matthew Logan Howard, Nathaniel Thomas Hubbard, Amanda E. Terry, James L. Chilenski, Mark Alan Ennever, Paul Chappell Ernst, Darin R. Greenwald, Martin J. Hughes, Jerry W. Marmar, Earl S. Porkolab, Miklos White, Anne E. Wolfe, Stephen M. Gao, Chi, Ph. D. Massachusetts Institute of Technology Non-local heat transport, rotation reversals and up/down impurity density asymmetries in Alcator C-Mod ohmic L-mode plasmas |
| title | Non-local heat transport, rotation reversals and up/down impurity density asymmetries in Alcator C-Mod ohmic L-mode plasmas |
| title_full | Non-local heat transport, rotation reversals and up/down impurity density asymmetries in Alcator C-Mod ohmic L-mode plasmas |
| title_fullStr | Non-local heat transport, rotation reversals and up/down impurity density asymmetries in Alcator C-Mod ohmic L-mode plasmas |
| title_full_unstemmed | Non-local heat transport, rotation reversals and up/down impurity density asymmetries in Alcator C-Mod ohmic L-mode plasmas |
| title_short | Non-local heat transport, rotation reversals and up/down impurity density asymmetries in Alcator C-Mod ohmic L-mode plasmas |
| title_sort | non local heat transport rotation reversals and up down impurity density asymmetries in alcator c mod ohmic l mode plasmas |
| url | http://hdl.handle.net/1721.1/81463 https://orcid.org/0000-0003-3234-8733 https://orcid.org/0000-0001-8319-5971 https://orcid.org/0000-0002-9518-4097 https://orcid.org/0000-0002-9604-204X https://orcid.org/0000-0003-2951-9749 https://orcid.org/0000-0002-4438-729X https://orcid.org/0000-0002-5283-0546 https://orcid.org/0000-0002-3616-8484 https://orcid.org/0000-0002-0026-6939 |
| work_keys_str_mv | AT diamondph nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT sunhj nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT cziegleristvan nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT podpalyya nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT rowanwl nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT delgadoaparicioluis nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT may nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT marmares nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT ricejohne nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT reinkematthewlogan nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT howardnathanielthomas nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT hubbardamandae nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT terryjamesl nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT chilenskimarkalan nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT enneverpaulchappell nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT ernstdarinr nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT greenwaldmartinj nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT hughesjerryw nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT marmarearls nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT porkolabmiklos nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT whiteannee nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT wolfestephenm nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas AT gaochiphdmassachusettsinstituteoftechnology nonlocalheattransportrotationreversalsandupdownimpuritydensityasymmetriesinalcatorcmodohmiclmodeplasmas |