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

Abstract

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.

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]
  1. Univ. of Wisconsin-Madison, Madison, WI (United States)
Publication Date:
Research Org.:
Univ. of Wisconsin-Madison, Madison, WI (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
OSTI Identifier:
1253176
Alternate Identifier(s):
OSTI ID: 1249936
Grant/Contract Number:  
FG02-96ER54375
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 116; Journal Issue: 17; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats

Thome, Kathreen E., Bongard, Michael W., Barr, Jayson L., Bodner, Grant M., Burke, Marcus G., Fonck, Raymond J., Kriete, David M., Perry, Justin M., and Schlossberg, David J. High confinement mode and edge localized mode characteristics in a near-unity aspect ratio tokamak. United States: N. p., 2016. Web. doi:10.1103/PhysRevLett.116.175001.
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. High confinement mode and edge localized mode characteristics in a near-unity aspect ratio tokamak. United States. doi:10.1103/PhysRevLett.116.175001.
Thome, Kathreen E., Bongard, Michael W., Barr, Jayson L., Bodner, Grant M., Burke, Marcus G., Fonck, Raymond J., Kriete, David M., Perry, Justin M., and Schlossberg, David J. Wed . "High confinement mode and edge localized mode characteristics in a near-unity aspect ratio tokamak". United States. doi:10.1103/PhysRevLett.116.175001. https://www.osti.gov/servlets/purl/1253176.
@article{osti_1253176,
title = {High confinement mode and edge localized mode characteristics in a near-unity aspect ratio tokamak},
author = {Thome, Kathreen E. and Bongard, Michael W. and Barr, Jayson L. and Bodner, Grant M. and Burke, Marcus G. and Fonck, Raymond J. and Kriete, David M. and Perry, Justin M. and Schlossberg, David J.},
abstractNote = {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 PLH 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 Jedge(R,t) measurements through an ELM that show a complex multimodal collapse and the ejection of a current-carrying filament.},
doi = {10.1103/PhysRevLett.116.175001},
journal = {Physical Review Letters},
issn = {0031-9007},
number = 17,
volume = 116,
place = {United States},
year = {2016},
month = {4}
}

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Works referenced in this record:

    Works referencing / citing this record:

    Public Data Set: H-mode Plasmas at Very Low Aspect Ratio on the Pegasus Toroidal Experiment
    dataset, January 2016


    Public Data Set: On Virial Analysis at Low Aspect Ratio
    dataset, July 2016

    • Bongard, Michael; Barr, Jayson; Fonck, Raymond
    • Pegasus-Supplementary information for journal article at DOI: 10.1063/1.4959808, 1 file (440 KB)
    • DOI: 10.18138/1240359

    Public Data Set: A Novel, Cost-Effective, Multi-Point Thomson Scattering System on the Pegasus Toroidal Experiment
    dataset, September 2016

    • Schlossberg, D. J.; Bodner, G. M.; Reusch, J. A.
    • AIP - Review of Scientific Instruments, Vol. 87, Issue 11, 49.6 MB
    • DOI: 10.18138/1257860

    Public Data Set: Control and Automation of the Pegasus Multi-point Thomson Scattering System
    dataset, January 2016

    • Bodner, Grant; Bongard, Michael; Fonck, Raymond
    • Pegasus, 13 files
    • DOI: 10.18138/1257971

    Public Data Set: A Power-Balance Model for Local Helicity Injection Startup in a Spherical Tokamak
    dataset, May 2018

    • Barr, J. L.; Bongard, M. W.; Burke, M. G.
    • Pegasus Public Data Sets
    • DOI: 10.18138/1345037

    Public Data Set: Non-inductively Driven Tokamak Plasmas at Near-Unity βt in the Pegasus Toroidal Experiment
    dataset, March 2018

    • Reusch, Joshua; Bodner, Grant; Bongard, Michael
    • Pegasus-Supplementary information for journal article at DOI: 10.1063/1.5017966, 1 file (5.1 MB)
    • DOI: 10.18138/1410490

    Public Data Set: Initiation and Sustainment of Tokamak Plasmas with Local Helicity Injection as the Majority Current Drive
    dataset, July 2018

    • 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)
    • DOI: 10.18138/1419641

    Public Data Set: Radially Scanning Magnetic Probes to Study Local Helicity Injection Dynamics
    dataset, July 2018

    • Richner, Nathan; Bongard, Michael; Fonck, Raymond
    • Pegasus-Supplementary information for journal article at DOI: 10.1063/1.5036527, 1 file (9.4 MB)
    • DOI: 10.18138/1432455