Resonant interaction of tearing modes with energetic-ions resulting in fishbone activities on HL-2A

Chen, W.; Zhu, Xiaolong; Wang, F.; Jiang, M.; Ji, X.Q.; Qiu, Zhiyong; Shi, Z.B.; Yu, D.L.; Li, Y.G.; Yu, Liming; Shi, P.W.; Ding, X.T.; Xu, M.; Wang, Z.X.

doi:10.1088/1741-4326/ab2bc6

Cited by 33 publications

(39 citation statements)

References 39 publications

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“…The equations in M3D-K code are solved for velocity stream function U, which is related to the incompressible part of the plasma velocity. The M3D-K code has been successfully and widely utilized to investigate TAE [25,29,30], sawteeth induced energetic-ion loss and redistribution [31], fishbone mode instability [32][33][34][35], beta-induced Alfvén eigenmode [36], the resonant interaction between tearing modes and energetic-ions [37,38] and reversed shear Alfvén eigenmodes [39]. In the present work, we mainly focus on the nonlinear simulation of TAE avalanche on NSTX, including n = 1-4 modes.…”

Section: Introductionmentioning

confidence: 99%

Avalanche transport of energetic-ions in magnetic confinement plasmas: nonlinear multiple wave-number simulation

et al. 2021

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Large burst activity, identified as toroidal Alfv\'{e}n eigenmode (TAE) avalanche, occurs frequently in neutral-beam heated plasmas in National Spherical Torus Experiment (NSTX). Based on the typical experimental observation of TAE avalanche on NSTX, a self-consistent nonlinear multiple wave-number ($k_{\parallel}\simeq n/R$, where $n$ toroidal mode-number and $R$ major radius) simulation associated with TAE avalanches is performed using the experimental parameters and profiles before the occurrence of TAE avalanche as the M3D-K input. The wave-wave nonlinear coupling among different modes and the resonant interaction between different modes and energetic-ions during TAE avalanches are identified in the nonlinear multiple wave-number simulations. The resonance overlap during the TAE avalanche is clearly observed in the simulation. It is found that the effective wave-wave coupling and a sufficiently strong drive are two important ingredients for the onset of TAE avalanches. TAE avalanche is considered to be a strongly nonlinear process and it is always accompanied by the simultaneous rapid frequency-chirping and large amplitude bursting of multiple modes and significant energetic-ion losses. The experimental phenomenon is observed on NSTX and is qualitatively reproduced by the simulation results in this work. These findings indicate that the onset of avalanche is triggered by nonlinearity of the system, and are also conducive to understanding the underlying mechanism of avalanche transport of energetic particles in the future burning plasmas, such as ITER.

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Section: Introductionmentioning

confidence: 99%

Avalanche transport of energetic-ions in magnetic confinement plasmas: nonlinear multiple wave-number simulation

et al. 2021

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“…Recently, a new experimental phenomenon associated with the interaction between the energetic-ions and the TM has been reported [25]. It is found that the resonant interaction between m/n = 2/1 TM and energetic-ions is observed on HL-2A, accompanied by amplitude-bursting/frequency-chirping fishbone-like activities, as shown in figure 1.…”

Section: Hybrid-kinetic Simulation Of Resonant Interaction Between En...mentioning

confidence: 93%

“…Since all of the experimental evidences indicate 1 < q 0 < 2 [25], the central value q 0 for the chosen safety factor q profiles ranges from 1.2 to 1.9 in the simulation, as shown in figure 2. The plasma density profile is assumed to be uniform.…”

Section: Experimental Phenomena and Simulation Setupmentioning

confidence: 99%

Hybrid-kinetic simulation of resonant interaction between energetic-ions and tearing modes in a tokamak plasma

et al. 2020

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The effect of energetic-ions on magnetohydrodynamic instabilities is pivotal in the basic physics that will be vital in burning plasma experiments. Recently, it has been found in the HL-2A tokamak that an m/n = 2/1 unstable tearing mode (TM) interacts with energeticions, resulting in amplitude-bursting and frequency-chirping fishbone-like activities, and it is numerically identified that the co-passing energetic-ions play a dominant role in the waveparticle resonances (Chen et al 2019 Nucl. Fusion 59 096037). Motivated by fully and deeply understanding such a resonant interaction between energetic-ions and TM, a more detailed study of global nonlinear hybrid kinetic-MHD simulations with M3D-K code is performed in the present work. The kinetic effect of co-passing energetic-ions from non-adiabatic response is interestingly found to be strongly destabilizing, while the net effect with both adiabatic and non-adiabatic contributions is weakly destabilizing. For passing energeticions, the m/n = 2/1 TM is found to be most unstable in the case of q 0 1.5, where q 0 is the central safety factor. Effects of energetic-ion beta β h and pinch angle Λ 0 determining different energetic-ion fractions on the resonance features, such as the growth rate, frequency chirping and mode structure, are discussed in detail. The relevant simulation results are consistent with the observations on HL-2A. Furthermore, the effects of both counter-passing and trapped energetic-ions on the TM have also been explored, but the corresponding resonance phase space is found to be very narrow in the P φ − E plane. In addition, the redistribution and loss induced by the resonant interaction between TM and energetic-ions are analyzed in multiplemode simulations. Significant redistribution and loss are clearly observed, and the scaling of energetic-ion loss fraction with the fluctuation amplitude is found to be f loss ∝ √ A max , indicating that the loss is convective. These discoveries are conducive to understanding the mechanisms of TM-induced energetic-ion loss through the resonant interaction.

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“…The fishbone modes are usually generated from interaction between energetic particles and 𝑚/𝑛 = 1/1 internal kink modes. Recently, the 𝑚/𝑛 = 2/1 fishbonelike modes with amplitude-bursting/frequencychirping phenomenons are firstly observed on HL-2A tokamak, [58,59] as given in Fig. 9.…”

Section: Reviewmentioning

confidence: 98%

Energetic Particle Physics on the HL-2A Tokamak: A Review

Shi¹,

Chen²,

Duan³

2021

Chinese Phys. Lett.

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Interaction between shear Alfvén wave (SAW) and energetic particles (EPs) is one of major concerns in magnetically confined plasmas since it may lead to excitation of toroidal symmetry breaking collective instabilities, thus enhances loss of EPs and degrades plasma confinement. In the last few years, Alfvénic zoology has been constructed on HL-2A tokamak and series of EPs driven instabilities, such as toroidal Alfvén eigenmodes (TAEs), revered shear Alfvén eigenmodes (RSAEs), beta induced Alfvén eigenmodes (BAEs), Alfvénic ion temperature gradient (AITG) modes and fishbone modes, have been observed and investigated. Those Alfvénic fluctuations show frequency chirping behaviors through nonlinear wave-particle route, and contribute to generation of axisymmetric modes by nonlinear wave-wave resonance in the presence of strong tearing modes. It is proved that the plasma confinement is affected by Alfvénic activities from multiple aspects. The RSAEs resonate with thermal ions, and this results in an energy diffusive transport process while the nonlinear mode coupling between core-localized TAEs and tearing modes trigger avalanche electron heat transport events. Effective measures have been taken to control SAW fluctuations and the fishbone activities are suppressed by electron cyclotron resonance heating. Those experimental results will not only contribute to better understandings of energetic particles physics, but also provide technology bases for active control of Alfvénic modes on International Thermonuclear Experimental Reactor (ITER) and Chinese Fusion Engineering Testing Reactor (CFETR).

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Resonant interaction of tearing modes with energetic-ions resulting in fishbone activities on HL-2A

Cited by 33 publications

References 39 publications

Avalanche transport of energetic-ions in magnetic confinement plasmas: nonlinear multiple wave-number simulation

Avalanche transport of energetic-ions in magnetic confinement plasmas: nonlinear multiple wave-number simulation

Hybrid-kinetic simulation of resonant interaction between energetic-ions and tearing modes in a tokamak plasma

Energetic Particle Physics on the HL-2A Tokamak: A Review

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