High confinement mode and edge localized mode characteristics in a near-unity aspect ratio tokamak

Thome, Kathreen E.; Bongard, Michael W.; Barr, Jayson L.; Bodner, Grant M.; Burke, Marcus G.; Fonck, Raymond J.; Kriete, David M.; Perry, Justin M.; Schlossberg, David J.

doi:10.1103/PhysRevLett.116.175001

High confinement mode and edge localized mode characteristics in a near-unity aspect ratio tokamak

Journal Article · Wed Apr 27 00:00:00 EDT 2016 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.116.175001· OSTI ID:1253176

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Univ. of Wisconsin-Madison, Madison, WI (United States); University of Wisconsin-Madison
Univ. of Wisconsin-Madison, Madison, WI (United States)

Tokamak experiments at near-unity aspect ratio A ≲ 1.2 offer new insights into the self-organized H-mode plasma confinement regime. In contrast to conventional A ~ 3 plasmas, the L–H power threshold P_LH is ~15× higher than scaling predictions, and it is insensitive to magnetic topology, consistent with modeling. Edge localized mode (ELM) instabilities shift to lower toroidal mode numbers as A decreases. Furthermore, these ultralow-A operations enable heretofore inaccessible J_edge(R,t) measurements through an ELM that show a complex multimodal collapse and the ejection of a current-carrying filament.

View Accepted Manuscript (DOE)

Research Organization:: Univ. of Wisconsin-Madison, Madison, WI (United States)

Sponsoring Organization:: USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)

Grant/Contract Number:: FG02-96ER54375

OSTI ID:: 1253176

Alternate ID(s):: OSTI ID: 1249936

Journal Information:: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 17 Vol. 116; ISSN 0031-9007; ISSN PRLTAO

Publisher:: American Physical Society (APS)Copyright Statement

Country of Publication:: United States

Language:: English

References (50)

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Public Data Set: H-mode Plasmas at Very Low Aspect Ratio on the Pegasus Toroidal Experiment Thome, Kathreen; Bongard, Michael; Barr, Jayson https://doi.org/10.18138/1236495	dataset	January 2016
Public Data Set: On Virial Analysis at Low Aspect Ratio Bongard, Michael; Barr, Jayson; Fonck, Raymond Pegasus-Supplementary information for journal article at DOI: 10.1063/1.4959808, 1 file (440 KB) https://doi.org/10.18138/1240359	dataset	July 2016
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Public Data Set: Control and Automation of the Pegasus Multi-point Thomson Scattering System Bodner, Grant; Bongard, Michael; Fonck, Raymond Pegasus, 13 files https://doi.org/10.18138/1257971	dataset	January 2016
Public Data Set: Erratum: "Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment" [Rev. Sci. Instrum. 83, 10D516 (2012)] Burke, Marcus; Fonck, Raymond; Bongard, Michael https://doi.org/10.18138/1259852	dataset	January 2016
Public Data Set: Continuous, Edge Localized Ion Heating During Non-Solenoidal Plasma Startup and Sustainment in a Low Aspect Ratio Tokamak Burke, Marcus; Barr, Jayson; Bongard, Michael https://doi.org/10.18138/1336395	dataset	January 2017
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Cited By (14)

A novel, cost-effective, multi-point Thomson scattering system on the Pegasus Toroidal Experiment (invited) Schlossberg, D. J.; Bodner, G. M.; Bongard, M. W. Review of Scientific Instruments, Vol. 87, Issue 11, Article No. 11E403 https://doi.org/10.1063/1.4962193	journal	September 2016
Public Data Set: High Confinement Mode and Edge Localized Mode Characteristics in a Near-Unity Aspect Ratio Tokamak Thome, Kathreen; Bongard, Michael; Barr, Jayson Pegasus, 13 files https://doi.org/10.18138/1209110	dataset	January 2016
Public Data Set: H-mode Plasmas at Very Low Aspect Ratio on the Pegasus Toroidal Experiment Thome, Kathreen; Bongard, Michael; Barr, Jayson https://doi.org/10.18138/1236495	dataset	January 2016
Public Data Set: On Virial Analysis at Low Aspect Ratio Bongard, Michael; Barr, Jayson; Fonck, Raymond Pegasus-Supplementary information for journal article at DOI: 10.1063/1.4959808, 1 file (440 KB) https://doi.org/10.18138/1240359	dataset	July 2016
Public Data Set: A Novel, Cost-Effective, Multi-Point Thomson Scattering System on the Pegasus Toroidal Experiment Schlossberg, D. J.; Bodner, G. M.; Reusch, J. A. AIP - Review of Scientific Instruments, Vol. 87, Issue 11, 49.6 MB https://doi.org/10.18138/1257860	dataset	September 2016
Public Data Set: Control and Automation of the Pegasus Multi-point Thomson Scattering System Bodner, Grant; Bongard, Michael; Fonck, Raymond Pegasus, 13 files https://doi.org/10.18138/1257971	dataset	January 2016
Public Data Set: Erratum: "Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment" [Rev. Sci. Instrum. 83, 10D516 (2012)] Burke, Marcus; Fonck, Raymond; Bongard, Michael https://doi.org/10.18138/1259852	dataset	January 2016
Public Data Set: Continuous, Edge Localized Ion Heating During Non-Solenoidal Plasma Startup and Sustainment in a Low Aspect Ratio Tokamak Burke, Marcus; Barr, Jayson; Bongard, Michael https://doi.org/10.18138/1336395	dataset	January 2017
Public Data Set: A Power-Balance Model for Local Helicity Injection Startup in a Spherical Tokamak Barr, J. L.; Bongard, M. W.; Burke, M. G. Pegasus Public Data Sets https://doi.org/10.18138/1345037	dataset	May 2018
Public Data Set: Non-inductively Driven Tokamak Plasmas at Near-Unity βt in the Pegasus Toroidal Experiment Reusch, Joshua; Bodner, Grant; Bongard, Michael Pegasus-Supplementary information for journal article at DOI: 10.1063/1.5017966, 1 file (5.1 MB) https://doi.org/10.18138/1410490	dataset	March 2018
Public Data Set: Initiation and Sustainment of Tokamak Plasmas with Local Helicity Injection as the Majority Current Drive Perry, Justin; Bodner, Grant; Bongard, Michael Pegasus-Supplementary information for journal article at DOI: https://doi.org/10.1088/1741-4326/aac72e, 1 file (17.1 MB) https://doi.org/10.18138/1419641	dataset	July 2018
Public Data Set: Radially Scanning Magnetic Probes to Study Local Helicity Injection Dynamics Richner, Nathan; Bongard, Michael; Fonck, Raymond Pegasus-Supplementary information for journal article at DOI: 10.1063/1.5036527, 1 file (9.4 MB) https://doi.org/10.18138/1432455	dataset	July 2018
Public Data Set: Spatial Heterodyne Spectroscopy for High Speed Measurements of Stark Split Neutral Beam Emission in a High Temperature Plasma Burke, Marcus; Fonck, Raymond; McKee, George University of Wisconsin-Madison https://doi.org/10.18138/1435641	dataset	January 2018
Public Data Set: Advancing Local Helicity Injection for Non-Solenoidal Tokamak Startup Bongard, Michael; Bodner, Grant; Burke, Marcus University of Wisconsin-Madison https://doi.org/10.18138/1489772	dataset	January 2019