Observation of trapped-electron-mode microturbulence in reversed field pinch plasmas

Duff, J. R.; Williams, Z. R.; Brower, D. L.; Chapman, B. E.; Ding, W. X.; Pueschel, M. J.; Sarff, J. S.; Terry, P. W.

doi:10.1063/1.5010198

Title: Observation of trapped-electron-mode microturbulence in reversed field pinch plasmas

Journal Article · Sat Dec 29 00:00:00 EST 2018 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.5010198· OSTI ID:1524582

^[1];

^[1]; Brower, D. L. ^[2];

^[1]; Ding, W. X. ^[2]; Pueschel, M. J. ^[1]; Sarff, J. S. ^[1]; Terry, P. W. ^[1]

Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics
Univ. of California, Los Angeles, CA (United States). Dept. of Physics and Astronomy

Density fluctuations in the large-density-gradient region of improved confinement Madison Symmetric Torus reversed field pinch (RFP) plasmas exhibit multiple features that are characteristic of the trapped-electron mode (TEM). Core transport in conventional RFP plasmas is governed by magnetic stochasticity stemming from multiple long-wavelength tearing modes. Using inductive current profile control, these tearing modes are reduced, and global confinement is increased to that expected for comparable tokamak plasmas. Under these conditions, new short-wavelength fluctuations distinct from global tearing modes appear in the spectrum at a frequency of f ~ 50 kHz, which have normalized perpendicular wave numbers k_⊥ρ_s≲0.2 and propagate in the electron diamagnetic drift direction. They exhibit a critical-gradient threshold, and the fluctuation amplitude increases with the local electron density gradient. These characteristics are consistent with predictions from gyrokinetic analysis using the Gene code, including increased TEM turbulence and transport from the interaction of remnant tearing magnetic fluctuations and zonal flow.

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Research Organization:: Univ. of Wisconsin, Madison, WI (United States); Univ. of California, Los Angeles, CA (United States)

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

Grant/Contract Number:: FC02-05ER54814; FG02-01ER54615

OSTI ID:: 1524582

Alternate ID(s):: OSTI ID: 1415156

Journal Information:: Physics of Plasmas, Vol. 25, Issue 1; ISSN 1070-664X

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

Country of Publication:: United States

Language:: English

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Cited by: 9 works

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References (46)

Experimental observation of turbulence transition and a critical gradient threshold for trapped electron mode in tokamak plasmas Zhong, W. L.; Shi, Z. B.; Yang, Z. J. Physics of Plasmas, Vol. 23, Issue 6 https://doi.org/10.1063/1.4953427	journal	June 2016
Overview of gyrokinetic studies of finite- β microturbulence Terry, P. W.; Carmody, D.; Doerk, H. Nuclear Fusion, Vol. 55, Issue 10 https://doi.org/10.1088/0029-5515/55/10/104011	journal	June 2015
Observation of a Critical Gradient Threshold for Electron Temperature Fluctuations in the DIII-D Tokamak Hillesheim, J. C.; DeBoo, J. C.; Peebles, W. A. Physical Review Letters, Vol. 110, Issue 4 https://doi.org/10.1103/PhysRevLett.110.045003	journal	January 2013
Fluctuation characteristics and transport properties of collisionless trapped electron mode turbulence Xiao, Yong; Holod, Ihor; Zhang, Wenlu Physics of Plasmas, Vol. 17, Issue 2 https://doi.org/10.1063/1.3302504	journal	February 2010
Fluctuations and anomalous transport in tokamaks Wootton, A. J.; Carreras, B. A.; Matsumoto, H. Physics of Fluids B: Plasma Physics, Vol. 2, Issue 12 https://doi.org/10.1063/1.859358	journal	December 1990
Experimental Electron Temperature Gradient Dependence of Heavy Impurity Transport in Fusion Devices Villegas, D.; Guirlet, R.; Bourdelle, C. Physical Review Letters, Vol. 105, Issue 3 https://doi.org/10.1103/PhysRevLett.105.035002	journal	July 2010
Convective Velocity Reversal Caused by Turbulence Transition in Tokamak Plasma Zhong, W. L.; Zou, X. L.; Bourdelle, C. Physical Review Letters, Vol. 111, Issue 26 https://doi.org/10.1103/PhysRevLett.111.265001	journal	December 2013
Self-organized helical equilibria as a new paradigm for ohmically heated fusion plasmas Lorenzini, R.; Martines, E.; Piovesan, P. Nature Physics, Vol. 5, Issue 8 https://doi.org/10.1038/nphys1308	journal	June 2009
Microturbulence studies of pulsed poloidal current drive discharges in the reversed field pinch Carmody, D.; Pueschel, M. J.; Anderson, J. K. Physics of Plasmas, Vol. 22, Issue 1 https://doi.org/10.1063/1.4905709	journal	January 2015
The Madison Symmetric Torus Dexter, R. N.; Kerst, D. W.; Lovell, T. W. Fusion Technology, Vol. 19, Issue 1 https://doi.org/10.13182/FST91-A29322	journal	January 1991
An investigation of density fluctuations and electron transport in the Madison Symmetric Torus reversed-field pinch Lanier, N. E.; Craig, D.; Anderson, J. K. Physics of Plasmas, Vol. 8, Issue 7 https://doi.org/10.1063/1.1378328	journal	July 2001
Simulation of ion temperature gradient turbulence in tokamaks Dimits, A. M.; Cohen, B. I.; Mattor, N. Nuclear Fusion, Vol. 40, Issue 3Y https://doi.org/10.1088/0029-5515/40/3Y/329	journal	March 2000
Electron temperature gradient driven turbulence Jenko, F.; Dorland, W.; Kotschenreuther, M. Physics of Plasmas, Vol. 7, Issue 5 https://doi.org/10.1063/1.874014	journal	May 2000
Measurement of magnetic fluctuation induced energy transport Fiksel, G.; Prager, S. C.; Shen, W. Physical Review Letters, Vol. 72, Issue 7 https://doi.org/10.1103/PhysRevLett.72.1028	journal	February 1994
Gyrokinetic turbulence simulations at high plasma beta Pueschel, M. J.; Kammerer, M.; Jenko, F. Physics of Plasmas, Vol. 15, Issue 10 https://doi.org/10.1063/1.3005380	journal	October 2008
E×B flow shear and enhanced confinement in the Madison Symmetric Torus reversed-field pinch Chapman, B. E.; Almagri, A. F.; Anderson, J. K. Physics of Plasmas, Vol. 5, Issue 5 https://doi.org/10.1063/1.872855	journal	May 1998
Role of Nonlinear Coupling and Density Fluctuations in Magnetic-Fluctuation-Induced Particle Transport Lin, L.; Ding, W. X.; Brower, D. L. Physical Review Letters, Vol. 108, Issue 17 https://doi.org/10.1103/PhysRevLett.108.175001	journal	April 2012
Role of density gradient driven trapped electron mode turbulence in the H-mode inner core with electron heating Ernst, D. R.; Burrell, K. H.; Guttenfelder, W. Physics of Plasmas, Vol. 23, Issue 5 https://doi.org/10.1063/1.4948723	journal	May 2016
Gyrokinetic studies of trapped electron mode turbulence in the Helically Symmetric eXperiment stellarator Faber, B. J.; Pueschel, M. J.; Proll, J. H. E. Physics of Plasmas, Vol. 22, Issue 7 https://doi.org/10.1063/1.4926510	journal	July 2015
Microtearing Modes in Reversed Field Pinch Plasmas Predebon, I.; Sattin, F.; Veranda, M. Physical Review Letters, Vol. 105, Issue 19 https://doi.org/10.1103/PhysRevLett.105.195001	journal	November 2010
Extreme Heat Fluxes in Gyrokinetic Simulations: A New Critical $β$ Pueschel, M. J.; Terry, P. W.; Jenko, F. Physical Review Letters, Vol. 110, Issue 15 https://doi.org/10.1103/PhysRevLett.110.155005	journal	April 2013
Profile stiffness and global confinement Garbet, X.; Mantica, P.; Ryter, F. Plasma Physics and Controlled Fusion, Vol. 46, Issue 9 https://doi.org/10.1088/0741-3335/46/9/002	journal	July 2004
Ion temperature gradient turbulence in helical and axisymmetric RFP plasmas Predebon, I.; Xanthopoulos, P. Physics of Plasmas, Vol. 22, Issue 5 https://doi.org/10.1063/1.4921645	journal	May 2015
Experimental Determination of Critical Threshold in Electron Transport on Tore Supra Hoang, G. T.; Bourdelle, C.; Garbet, X. Physical Review Letters, Vol. 87, Issue 12 https://doi.org/10.1103/PhysRevLett.87.125001	journal	September 2001
Tokamak-like confinement at high beta and low field in the reversed field pinch Sarff, J. S.; Anderson, J. K.; Biewer, T. M. Plasma Physics and Controlled Fusion, Vol. 45, Issue 12A https://doi.org/10.1088/0741-3335/45/12A/029	journal	November 2003
Turbulence, transport, and zonal flows in the Madison symmetric torus reversed-field pinch Williams, Z. R.; Pueschel, M. J.; Terry, P. W. Physics of Plasmas, Vol. 24, Issue 12 https://doi.org/10.1063/1.5000252	journal	December 2017
Generation and confinement of hot ions and electrons in a reversed-field pinch plasma Chapman, B. E.; Almagri, A. F.; Anderson, J. K. Plasma Physics and Controlled Fusion, Vol. 52, Issue 12 https://doi.org/10.1088/0741-3335/52/12/124048	journal	November 2010
Enhanced Confinement with Plasma Biasing in the MST Reversed Field Pinch Craig, D.; Almagri, A. F.; Anderson, J. K. Physical Review Letters, Vol. 79, Issue 10 https://doi.org/10.1103/PhysRevLett.79.1865	journal	September 1997
Electron Heat Transport Measured in a Stochastic Magnetic Field Biewer, T. M.; Forest, C. B.; Anderson, J. K. Physical Review Letters, Vol. 91, Issue 4 https://doi.org/10.1103/PhysRevLett.91.045004	journal	July 2003
High-frequency fluctuation measurements by far-infrared laser Faraday-effect polarimetry-interferometry and forward scattering system on MST Ding, W. X.; Lin, L.; Duff, J. R. Review of Scientific Instruments, Vol. 85, Issue 11 https://doi.org/10.1063/1.4889909	journal	November 2014
Reduced Edge Instability and Improved Confinement in the MST Reversed-Field Pinch Chapman, B. E.; Anderson, J. K.; Biewer, T. M. Physical Review Letters, Vol. 87, Issue 20 https://doi.org/10.1103/PhysRevLett.87.205001	journal	October 2001
Measurements of microturbulence in tokamaks and comparisons with theories of turbulence and anomalous transport Liewer, Paulett C. Nuclear Fusion, Vol. 25, Issue 5 https://doi.org/10.1088/0029-5515/25/5/004	journal	May 1985
Experimental Evidence for a Reduction in Electron Thermal Diffusion due to Trapped Particles Reusch, J. A.; Anderson, J. K.; Den Hartog, D. J. Physical Review Letters, Vol. 107, Issue 15 https://doi.org/10.1103/PhysRevLett.107.155002	journal	October 2011
Role of trapped electron mode turbulence in internal transport barrier control in the Alcator C-Mod Tokamak Ernst, D. R.; Bonoli, P. T.; Catto, P. J. Physics of Plasmas, Vol. 11, Issue 5 https://doi.org/10.1063/1.1705653	journal	May 2004
Quasi-coherent modes and electron-driven turbulence Arnichand, H.; Sabot, R.; Hacquin, S. Nuclear Fusion, Vol. 54, Issue 12 https://doi.org/10.1088/0029-5515/54/12/123017	journal	November 2014
Origin of Magnetic Stochasticity and Transport in Plasma Microturbulence Hatch, D. R.; Pueschel, M. J.; Jenko, F. Physical Review Letters, Vol. 108, Issue 23 https://doi.org/10.1103/PhysRevLett.108.235002	journal	June 2012
Laser polarimetric measurement of equilibrium and fluctuating magnetic fields in a reversed field pinch (invited) Brower, D. L.; Ding, W. X.; Terry, S. D. Review of Scientific Instruments, Vol. 74, Issue 3 https://doi.org/10.1063/1.1526927	journal	March 2003
The effect of magnetic flutter on residual flow Terry, P. W.; Pueschel, M. J.; Carmody, D. Physics of Plasmas, Vol. 20, Issue 11 https://doi.org/10.1063/1.4828396	journal	November 2013
Measurement of the Current-Density Profile and Plasma Dynamics in the Reversed-Field Pinch Brower, D. L.; Ding, W. X.; Terry, S. D. Physical Review Letters, Vol. 88, Issue 18 https://doi.org/10.1103/PhysRevLett.88.185005	journal	April 2002
Stiff temperature profiles in JT-60U ELMy H-mode plasmas Mikkelsen, D. R.; Shirai, H.; Urano, H. Nuclear Fusion, Vol. 43, Issue 1 https://doi.org/10.1088/0029-5515/43/1/304	journal	December 2002
Core density turbulence in the HSX Stellarator Deng, C. B.; Brower, D. L.; Anderson, D. T. Nuclear Fusion, Vol. 55, Issue 12 https://doi.org/10.1088/0029-5515/55/12/123003	journal	October 2015
Equilibrium reconstruction in the Madison Symmetric Torus reversed field pinch Anderson, J. K.; Forest, C. B.; Biewer, T. M. Nuclear Fusion, Vol. 44, Issue 1 https://doi.org/10.1088/0029-5515/44/1/018	journal	December 2003
Gyrokinetic studies of microinstabilities in the reversed field pinch Carmody, D.; Pueschel, M. J.; Terry, P. W. Physics of Plasmas, Vol. 20, Issue 5 https://doi.org/10.1063/1.4803509	journal	May 2013
Magnetic-Fluctuation-Induced Particle Transport and Density Relaxation in a High-Temperature Plasma Ding, W. X.; Brower, D. L.; Fiksel, G. Physical Review Letters, Vol. 103, Issue 2 https://doi.org/10.1103/PhysRevLett.103.025001	journal	July 2009
Identification of trapped electron modes in frequency fluctuation spectra Arnichand, H.; Citrin, J.; Hacquin, S. Plasma Physics and Controlled Fusion, Vol. 58, Issue 1 https://doi.org/10.1088/0741-3335/58/1/014037	journal	November 2015
Fluctuation and transport reduction in a reversed field pinch by inductive poloidal current drive Sarff, J. S.; Hokin, S. A.; Ji, H. Physical Review Letters, Vol. 72, Issue 23 https://doi.org/10.1103/PhysRevLett.72.3670	journal	June 1994

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