On virial analysis at low aspect ratio

Bongard, Michael W.; Barr, Jayson L.; Fonck, Raymond J.; Reusch, Joshua A.; Thome, Kathreen E.

doi:10.1063/1.4959808

Title: On virial analysis at low aspect ratio

Journal Article · Thu Jul 28 00:00:00 EDT 2016 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.4959808· OSTI ID:1275599

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Univ. of Wisconsin-Madison, Madison, WI (United States)
Univ. of Wisconsin-Madison, Madison, WI (United States); Oak Ridge Associated Univ., Oak Ridge, TN (United States)

The validity of virial analysis to infer global MHD equilibrium poloidal beta β_p and internal inductance ℓ_i from external magnetics measurements is examined for low aspect ratio configurations with A < 2. Numerical equilibrium studies at varied aspect ratio are utilized to validate the technique at finite aspect ratio. The effect of applying high-A approximations to low-A experimental data is quantified and demonstrates significant over-estimation of stored energy (factors of 2–10) in spherical tokamak geometry. Experimental approximations to equilibrium-dependent volume integral terms in the analysis are evaluated at low-A. Highly paramagnetic configurations are found to be inadequately represented through the virial mean radius parameter R_T. Alternate formulations for inferring β_p and ℓ_i that are independent of R_T to avoid this difficulty are presented for the static isotropic limit. Lastly, these formulations are suitable for fast estimation of tokamak stored energy components at low aspect ratio using virial analysis.

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

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

Grant/Contract Number:: FG02-96ER54375

OSTI ID:: 1275599

Alternate ID(s):: OSTI ID: 1274826

Journal Information:: Physics of Plasmas, Vol. 23, Issue 7; Related Information: M.W. Bongard, J.L. Barr, R.J. Fonck, J.A. Reusch, and K.E. Thome, "Public Data Set: On Virial Analysis at Low Aspect Ratio," DOI: 10.18138/1240359; ISSN 1070-664X

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

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Cited by: 4 works

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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
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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: 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

Cited By (11)

Simple and accurate method of diamagnetic flux measurement in Versatile Experimental Spherical Torus (VEST) Yang, J.; Kim, Y.; Jeong, W. I. Review of Scientific Instruments, Vol. 89, Issue 10 https://doi.org/10.1063/1.5041517	journal	October 2018
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: 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