Mode rotation control in a tokamak with a feedback-driven biased electrode

Brooks, J. W.; Stewart, I. G.; Boyer, M. D.; Levesque, J. P.; Mauel, M. E.; Navratil, G. A.

doi:10.1063/1.5062271

Title: Mode rotation control in a tokamak with a feedback-driven biased electrode

Journal Article · Fri Feb 22 00:00:00 EST 2019 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.5062271· OSTI ID:1512695

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Columbia Univ., New York, NY (United States)
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Rotation of the plasma and MHD modes in tokamaks has been shown to stabilize resistive wall and tearing modes as well as improve confinement through suppression of edge turbulence. In this work, we control mode rotation with a biased electrode inserted into the plasma of the High Beta Tokamak-Extended Pulse’s facility in conjunction with its active GPU (Graphical Processing Unit) feedback system. We first characterize a negative linear relationship between the electrode voltage and mode rotation. Using this relationship, we design, simulate, and implement a proof-of-concept, GPU-based active-control system, which shows consistent success in controlling mode rotation in both feedforward and feedback operation. Controllability is limited by operating conditions, the electrode’s voltage range, and by the electrode’s proximity to the vessel’s walls. The final control system has a 15 μs cycle time, but the addition of various signal filters results in a full cycle latency of 200 μs.

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Research Organization:: Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

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

Grant/Contract Number:: FG02-86ER53222; SC0014664

OSTI ID:: 1512695

Journal Information:: Review of Scientific Instruments, Vol. 90, Issue 2; ISSN 0034-6748

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

Country of Publication:: United States

Language:: English

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Cited by: 6 works

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References (21)

Simultaneous feedback control of plasma rotation and stored energy on the DIII-D tokamak Scoville, J. T.; Humphreys, D. A.; Ferron, J. R. Fusion Engineering and Design, Vol. 82, Issue 5-14 https://doi.org/10.1016/j.fusengdes.2007.04.031	journal	October 2007
Effect of magnetic islands on the local plasma behavior in a tokamak experiment Taylor, E. D.; Cates, C.; Mauel, M. E. Physics of Plasmas, Vol. 9, Issue 9 https://doi.org/10.1063/1.1499715	journal	September 2002
Improved feedback control of wall stabilized kink modes with different plasma–wall couplings and mode rotation Peng, Q.; Levesque, J. P.; Stoafer, C. C. Plasma Physics and Controlled Fusion, Vol. 58, Issue 4 https://doi.org/10.1088/0741-3335/58/4/045001	journal	January 2016
Relationship between onset thresholds, trigger types and rotation shear for the m / n = 2/1 neoclassical tearing mode in a high-β spherical torus Gerhardt, S. P.; Brennan, D. P.; Buttery, R. Nuclear Fusion, Vol. 49, Issue 3 https://doi.org/10.1088/0029-5515/49/3/032003	journal	March 2009
Nondestructive synchronous beam current monitor Covo, Michel Kireeff Review of Scientific Instruments, Vol. 85, Issue 12 https://doi.org/10.1063/1.4902903	journal	December 2014
Controlled Fusion and Plasma Physics Engelmann, F. Plasma Physics and Controlled Fusion, Vol. 49, Issue 7 https://doi.org/10.1088/0741-3335/49/7/b01	journal	June 2007
Effect of toroidal plasma flow and flow shear on global magnetohydrodynamic MHD modes Chu, M. S.; Greene, J. M.; Jensen, T. H. Physics of Plasmas, Vol. 2, Issue 6 https://doi.org/10.1063/1.871247	journal	June 1995
Modeling and control of plasma rotation for NSTX using neoclassical toroidal viscosity and neutral beam injection Goumiri, I. R.; Rowley, C. W.; Sabbagh, S. A. Nuclear Fusion, Vol. 56, Issue 3 https://doi.org/10.1088/0029-5515/56/3/036023	journal	February 2016
A novel approach for mitigating disruptions using biased electrode in Aditya tokamak Dhyani, Pravesh; Ghosh, J.; Chattopadhyay, P. K. Nuclear Fusion, Vol. 54, Issue 8 https://doi.org/10.1088/0029-5515/54/8/083023	journal	June 2014
The high beta tokamak-extended pulse magnetohydrodynamic mode control research program Maurer, D. A.; Bialek, J.; Byrne, P. J. Plasma Physics and Controlled Fusion, Vol. 53, Issue 7 https://doi.org/10.1088/0741-3335/53/7/074016	journal	May 2011
Adaptive control of rotating magnetic perturbations in HBT-EP using GPU processing Rath, N.; Angelini, S.; Bialek, J. Plasma Physics and Controlled Fusion, Vol. 55, Issue 8 https://doi.org/10.1088/0741-3335/55/8/084003	journal	June 2013
Dynamics of MHD instabilities near a ferromagnetic wall Hughes, P. E.; Levesque, J. P.; Navratil, G. A. Nuclear Fusion, Vol. 58, Issue 12 https://doi.org/10.1088/1741-4326/aade58	journal	September 2018
Tokamak edge plasma rotation in the presence of the biased electrode Ghoranneviss, M.; Mohammadi, S.; Elahi, A. Salar Fusion Engineering and Design, Vol. 88, Issue 2 https://doi.org/10.1016/j.fusengdes.2012.12.001	journal	February 2013
The interaction between plasma rotation, stochastic fields and tearing mode excitation by external perturbation fields De Bock, M. F. M.; Classen, I. G. J.; Busch, C. Nuclear Fusion, Vol. 48, Issue 1 https://doi.org/10.1088/0029-5515/48/1/015007	journal	January 2008
The Experimental Results of MHD Instability Suppression with Electrode Biasing in the HT-7 Tokamak Shu, Shuangbao; Luo, Jiarong; Wang, Huazhong Journal of Fusion Energy, Vol. 34, Issue 3 https://doi.org/10.1007/s10894-015-9868-9	journal	January 2015
H-mode behavior induced by cross-field currents in a tokamak Taylor, R.; Brown, M.; Fried, B. Physical Review Letters, Vol. 63, Issue 21 https://doi.org/10.1103/physrevlett.63.2365	journal	November 1989
MHD-mode locking by controlled halo-current in the T-10 tokamak Chudnovskiy, A. N.; Gvozdkov, Yu. V.; Ivanov, N. V. Nuclear Fusion, Vol. 43, Issue 8 https://doi.org/10.1088/0029-5515/43/8/307	journal	July 2003
Application of benchmarked kinetic resistive wall mode stability codes to ITER, including additional physics Berkery, J. W.; Wang, Z. R.; Sabbagh, S. A. Physics of Plasmas, Vol. 24, Issue 11 https://doi.org/10.1063/1.4989503	journal	November 2017
Understanding Langmuir probe current-voltage characteristics Merlino, Robert L. American Journal of Physics, Vol. 75, Issue 12 https://doi.org/10.1119/1.2772282	journal	December 2007
Real-time measurement and feedback control of ion temperature profile and toroidal rotation using fast CXRS system in JT-60U Yoshida, M.; Sakamoto, Y.; Sueoka, M. Fusion Engineering and Design, Vol. 84, Issue 12 https://doi.org/10.1016/j.fusengdes.2009.04.006	journal	December 2009
Effect of electrode biasing on m / n = 2/1 tearing modes in J-TEXT experiments Liu, Hai; Hu, Qiming; Chen, Zhipeng Nuclear Fusion, Vol. 57, Issue 1 https://doi.org/10.1088/0029-5515/57/1/016003	journal	September 2016

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