Measurement of small island characteristics using high resolution ECE and CER at DIII-D

Yang, J.; Fredrickson, E. D.; Hu, Q.; Podestà, M.; Berkery, J. W.; Bardóczi, L.; La Haye, R. J.; Sauter, O.; Austin, M.; Strait, E.; Chrystal, C.

doi:10.1088/1361-6587/ad75b8

Measurement of small island characteristics using high resolution ECE and CER at DIII-D

Journal Article · Tue Sep 10 00:00:00 EDT 2024 · Plasma Physics and Controlled Fusion

DOI:https://doi.org/10.1088/1361-6587/ad75b8· OSTI ID:2440306

; Fredrickson, E. D.; ; ; ; ; La Haye, R. J.; ; Austin, M.; ;

Abstract

The measurements using the high resolution electron cyclotron emission radiometry and the charge exchange and recombination spectroscopy are processed using analytic formulas to allow for the detection of islands as small as 1.9 cm. In contrast to large, saturated magnetic islands which are relatively well understood to be governed by the loss of bootstrap current inside the island, small islands are less well understood due to the difficulty of their accurate measurement in tokamaks. Here, ‘small’ islands are islands comparable in size to the ion banana width, which can be as small as 0.8 cm at DIII-D. The new measurement methods allow for the detection of small island widths when the predicted increase of mode frequency to match the Doppler shifted ion diamagnetic frequency is observed. Therefore, for the first time, the mode frequency increase can be unambiguously associated to the acceleration of the magnetic island propagation. Such association allows for a further development and validation of the much-debated theory of ion polarization currents, which is thought to govern the small island growth.

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

Grant/Contract Number:: AC02-09CH11466

OSTI ID:: 2440306

Alternate ID(s):: OSTI ID: 2440716
OSTI ID: 2510808

Journal Information:: Plasma Physics and Controlled Fusion, Journal Name: Plasma Physics and Controlled Fusion Journal Issue: 10 Vol. 66; ISSN 0741-3335

Publisher:: IOP PublishingCopyright Statement

Country of Publication:: United Kingdom

Language:: English

References (27)

The role of polarization current in magnetic island evolution Connor, J. W.; Waelbroeck, F. L.; Wilson, H. R. Physics of Plasmas, Vol. 8, Issue 6 https://doi.org/10.1063/1.1370062	journal	June 2001
Interaction of neoclassical tearing modes with trapped fast ions Marchenko, V. S.; Lutsenko, V. V. Physics of Plasmas, Vol. 8, Issue 11 https://doi.org/10.1063/1.1407283	journal	November 2001
Electron cyclotron emission radiometer upgrade on the DIII-D tokamak Austin, M. E.; Lohr, J. Review of Scientific Instruments, Vol. 74, Issue 3 https://doi.org/10.1063/1.1530387	journal	March 2003
Propagation of magnetic islands in the Er=0 frame of co-injected neutral beam driven discharges in the DIII-D tokamak La Haye, R. J.; Petty, C. C.; Strait, E. J. Physics of Plasmas, Vol. 10, Issue 9 https://doi.org/10.1063/1.1602452	journal	September 2003
Nonlinear growth of the tearing mode Rutherford, P. H. Physics of Fluids, Vol. 16, Issue 11 https://doi.org/10.1063/1.1694232	journal	January 1973
Finite-Resistivity Instabilities of a Sheet Pinch Furth, Harold P.; Killeen, John; Rosenbluth, Marshall N. Physics of Fluids, Vol. 6, Issue 4 https://doi.org/10.1063/1.1706761	journal	January 1963
Improved charge-coupled device detectors for high-speed, charge exchange spectroscopy studies on the DIII-D tokamak Burrell, K. H.; Gohil, P.; Groebner, R. J. Review of Scientific Instruments, Vol. 75, Issue 10 https://doi.org/10.1063/1.1787949	journal	October 2004
Magnetic diagnostic system of the DIII-D tokamak Strait, E. J. Review of Scientific Instruments, Vol. 77, Issue 2 https://doi.org/10.1063/1.2166493	journal	February 2006
Experimental test of the neoclassical theory of impurity poloidal rotation in tokamaks Solomon, W. M.; Burrell, K. H.; Andre, R. Physics of Plasmas, Vol. 13, Issue 5 https://doi.org/10.1063/1.2180728	journal	May 2006
High spatial resolution upgrade of the electron cyclotron emission radiometer for the DIII-D tokamak Truong, D. D.; Austin, M. E. Review of Scientific Instruments, Vol. 85, Issue 11 https://doi.org/10.1063/1.4889737	journal	November 2014
An upgrade of the magnetic diagnostic system of the DIII-D tokamak for non-axisymmetric measurements King, J. D.; Strait, E. J.; Boivin, R. L. Review of Scientific Instruments, Vol. 85, Issue 8 https://doi.org/10.1063/1.4891817	journal	August 2014
Non-perturbative measurement of cross-field thermal diffusivity reduction at the O-point of 2/1 neoclassical tearing mode islands in the DIII-D tokamak Bardóczi, L.; Rhodes, T. L.; Carter, T. A. Physics of Plasmas, Vol. 23, Issue 5 https://doi.org/10.1063/1.4948560	journal	May 2016
Island bootstrap current modification of the nonlinear dynamics of the tearing mode Carrera, R.; Hazeltine, R. D.; Kotschenreuther, M. Physics of Fluids, Vol. 29, Issue 4 https://doi.org/10.1063/1.865682	journal	January 1986
Rotating nonlinear magnetic islands in a tokamak plasma Smolyakov, A. I.; Hirose, A.; Lazzaro, E. Physics of Plasmas, Vol. 2, Issue 5 https://doi.org/10.1063/1.871308	journal	May 1995
Helical temperature perturbations associated with tearing modes in tokamak plasmas Fitzpatrick, Richard Physics of Plasmas, Vol. 2, Issue 3 https://doi.org/10.1063/1.871434	journal	March 1995
Beta limits in long-pulse tokamak discharges Sauter, O.; La Haye, R. J.; Chang, Z. Physics of Plasmas, Vol. 4, Issue 5 https://doi.org/10.1063/1.872270	journal	May 1997
Neoclassical tearing modes in Tokamak Fusion Test Reactor experiments. I. Measurements of magnetic islands and Δ ^′ Chang, Z.; Fredrickson, E. D.; Batha, S. H. Physics of Plasmas, Vol. 5, Issue 4 https://doi.org/10.1063/1.872627	journal	April 1998
Global energy confinement degradation due to macroscopic phenomena in tokamaks Chang, Z.; Callen, J. D. Nuclear Fusion, Vol. 30, Issue 2 https://doi.org/10.1088/0029-5515/30/2/003	journal	February 1990
Experiments on neoclassical tearing mode stabilization by ECCD in ASDEX Upgrade Zohm, H.; Gantenbein, G.; Giruzzi, G. Nuclear Fusion, Vol. 39, Issue 5 https://doi.org/10.1088/0029-5515/39/5/101	journal	May 1999
Complete suppression of the m = 2/ n = 1 neoclassical tearing mode using electron cyclotron current drive in DIII-D Petty, C. C.; Haye, R. J. La; Luce, T. C. Nuclear Fusion, Vol. 44, Issue 2 https://doi.org/10.1088/0029-5515/44/2/004	journal	January 2004
Survey of disruption causes at JET de Vries, P. C.; Johnson, M. F.; Alper, B. Nuclear Fusion, Vol. 51, Issue 5 https://doi.org/10.1088/0029-5515/51/5/053018	journal	April 2011
Suppressing magnetic island and accelerating its rotation by modulated resonant magnetic perturbation Hu, Qiming; Yu, Q. Nuclear Fusion, Vol. 56, Issue 3 https://doi.org/10.1088/0029-5515/56/3/034001	journal	February 2016
Diagnostic application of magnetic islands rotation in JET Buratti, P.; Alessi, E.; Baruzzo, M. Nuclear Fusion, Vol. 56, Issue 7 https://doi.org/10.1088/0029-5515/56/7/076004	journal	June 2016
Nonlinear growth of magnetic islands by passing fast ions in NSTX Yang, J.; Fredrickson, E. D.; Podestà, M. Plasma Physics and Controlled Fusion, Vol. 64, Issue 9 https://doi.org/10.1088/1361-6587/ac7970	journal	July 2022
MHD stability of negative triangularity DIII-D plasmas Boyes, W.; Turco, F.; Hanson, J. Nuclear Fusion, Vol. 63, Issue 8 https://doi.org/10.1088/1741-4326/acd564	journal	June 2023
Observation of Nonlinear Neoclassical Pressure-Gradient–Driven Tearing Modes in TFTR Chang, Z.; Callen, J. D.; Fredrickson, E. D. Physical Review Letters, Vol. 74, Issue 23 https://doi.org/10.1103/PhysRevLett.74.4663	journal	June 1995
Transp Breslau, Joshua; Gorelenkova, Marina; Poli, Francesca Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States) https://doi.org/10.11578/dc.20180627.4	software	June 2018

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