Observation of internal kink instability purely driven by suprathermal electrons in the HL-1M tokamak

Ding, X.T.; Liu, Yi; Guo, G.C.; Wang, E.Y.; Wong, K. L.; Yan, L.W.; Dong, J. Q.; Cao, Jianyong; Zhou, Yadong; Rao, J.; Yuan, Yifei; Xia, Hua; Liu, Yong

doi:10.1088/0029-5515/42/5/301

Cited by 57 publications

(63 citation statements)

References 18 publications

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“…Further demonstration of the nonlinear physics underlying the fishbone burst cycle has been recently provided for "electron fishbones" (e-fishbones) , due to precessional resonance with supra-thermal electrons (Ding et al, 2002;Wong et al, 2000;Zonca et al, 2007a). Their simulation results are consistent with those by and demonstrate that nonlinear mode saturation is accompanied by downward frequency chirping.…”

Section: The Fishbone Burst Cyclementioning

confidence: 64%

Physics of Alfvén waves and energetic particles in burning plasmas

2016

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Dynamics of shear Alfvén waves and energetic particles are crucial to the performance of burning fusion plasmas. This article reviews linear as well as nonlinear physics of shear Alfvén waves and their self-consistent interaction with energetic particles in tokamak fusion devices. More specifically, the review on the linear physics deals with wave spectral properties and collective excitations by energetic particles via wave-particle resonances. The nonlinear physics deals with nonlinear wave-wave interactions as well as nonlinear wave-energetic particle interactions. Both linear as well as nonlinear physics demonstrate the qualitatively important roles played by realistic equilibrium nonuniformities, magnetic field geometries, and the specific radial mode structures in determining the instability evolution, saturation, and, ultimately, energetic-particle transport. These topics are presented within a single unified theoretical framework, where experimental observations and numerical simulation results are referred to elucidate concepts and physics processes.

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Section: The Fishbone Burst Cyclementioning

confidence: 64%

Physics of Alfvén waves and energetic particles in burning plasmas

2016

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“…Electron fishbones driven only by HFS off-axis (near q = 1) ECRH were observed also in HL-1M tokamak [20]; applying LH waves was found to enhance the fishbone, but only in conjunction with ECRH. Meanwhile, the observation of fishbone oscillations driven by only LH waves has been reported on FTU [7,21,22] and Tore Supra [23,24].…”

Section: Experimental Evidences Of Energetic Electron Driven Fishbonesmentioning

confidence: 91%

Theory and modeling of electron fishbones

et al. 2016

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Internal kink instabilities exhibiting fishbone like behavior have been observed in a variety of experiments where a high energy electron population, generated by strong auxiliary heating and/or current drive systems, was present. After briefly reviewing the experimental evidences of energetic electrons driven fishbones, and the main results of linear and nonlinear theory of electron fishbones, the results of global, self-consistent, nonlinear hybrid MHD-Gyrokinetic simulations will be presented. To this purpose, the extended/hybrid MHD-Gyrokinetic code XHMGC will be used. Linear dynamics analysis will enlighten the effect of considering kinetic thermal ion compressibility and diamagnetic response, and kinetic thermal electrons compressibility, in addition to the energetic electron contribution. Nonlinear saturation and energetic electron transport will also be addressed, making extensive use of Hamiltonian mapping techniques, discussing both centrally peaked and offaxis peaked energetic electron profiles. It will be shown that centrally peaked energetic electron profiles are characterized by resonant excitation and nonlinear response of deeply trapped energetic electrons. On the other side, off-axis peaked energetic electron profiles are characterized by resonant excitation and nonlinear response of barely circulating energetic electrons which experience toroidal precession reversal of their motion.

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“…2 The FEB tomography system based on cadmium telluride ͑CdTe͒ detectors in Tore Supra has two independent pinhole cameras with 59 sight lines, which allow a detailed investigation of the low hybrid physics and the fast electron dynamics with very high accuracy level. [10][11][12][13] Although fishbone instability has been investigated for tens of years, the kinetic effect of fast electrons on fishbone mode has not been clear up to now. 5 It is well known that electron cyclotron resonance heating ͑ECRH͒ in tokamak plasma produces a non-Maxwellian velocity distribution, which can be idealized as a system of two separate Maxwellian distributions: one of the bulk electrons or the so-called thermal electrons and another one of the fast electrons or the so-called superthermal electrons.…”

Section: Measurements Of the Fast Electron Bremsstrahlung Emission Dumentioning

confidence: 99%

Measurements of the fast electron bremsstrahlung emission during electron cyclotron resonance heating in the HL-2A tokamak

Zhang

Liu

Song

et al. 2010

Review of Scientific Instruments

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A fast electron bremsstrahlung (FEB) diagnostic technique based on cadmium telluride (CdTe) detector has been developed recently in the HL-2A tokamak for measurements of the temporal evolution of FEB emission in the energy range of 10-200 keV. With a perpendicular viewing into the plasma on the equatorial plane, the hard x-ray spectra with eight different energy channels are measured. The discrimination of the spectra is implemented by an accurate spectrometry. The system also makes use of fast digitization and software signal processing technology. An ambient environment of neutrons, gammas, and magnetic disturbance requires careful shielding. During electron cyclotron resonance heating, the generation of fast electrons and the oscillations of electron fishbone (e-fishbone) have been found. Using the FEB measurement system, it has been experimentally identified that the mode strongly correlates with the electron cyclotron resonance heating produced fast electrons with 30-70 keV.

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Observation of internal kink instability purely driven by suprathermal electrons in the HL-1M tokamak

Cited by 57 publications

References 18 publications

Physics of Alfvén waves and energetic particles in burning plasmas

Physics of Alfvén waves and energetic particles in burning plasmas

Theory and modeling of electron fishbones

Measurements of the fast electron bremsstrahlung emission during electron cyclotron resonance heating in the HL-2A tokamak

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