Multiple interactions between fishbone instabilities and internal transport barriers in EAST plasmas

Ge, Wanling; Wang, Jialei; Wang, Feng; Liu, Zixi; Xu, Liqing

doi:10.1088/1741-4326/aca10c

Cited by 9 publications

(7 citation statements)

References 71 publications

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“…This saturation by zonal flows is confirmed by experimental measurements, as simulations including zonal flows are able to recover quantitatively, for the first time, the mode saturation amplitude and the neutron emissivity drop. Moreover, the shearing rate generated by the fishbone-induced zonal flows exceeds the linear growth rate of unstable drift-wave modes, similar to recent numerical work based on EAST discharges [21]. This strong E × B suppression is consistent with the ITB arising experimentally after fishbone bursts in the DIII-D discharge.…”

supporting

confidence: 87%

Saturation of fishbone instability by self-generated zonal flows in tokamak plasmas

Brochard¹,

Liu²,

Wei³

et al. 2023

Preprint

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Gyrokinetic and kinetic-MHD simulations of n=1 fishbone modes in DIII-D plasmas find that self-generated zonal flows can dominate the fishbone saturation. The saturation mechanism is identified in phase space, where the zonal flows prevent holes and clumps from persisting or drifting in phase space with mode down-chirping, reducing the wave-particle resonant drive. This saturation is confirmed by quantitative agreement with experimental measurements for both mode saturation amplitude and neutron emissivity. Zonal flows shearing rate exceeds the drift-wave growth rate, consistent with the ITB observed in DIII-D plasmas. The deliberate destabilization of fishbones for the development of high performance scenarios in ITER is then proposed.

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supporting

confidence: 87%

Saturation of fishbone instability by self-generated zonal flows in tokamak plasmas

Brochard¹,

Liu²,

Wei³

et al. 2023

Preprint

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“…Moreover, the EPs parts are described by drift-kinetic equations, which are calculated by δƒ particle-in-cell method. So far, the code has been effectively applied to investigate fishbones, tearing modes, RSAEs, TAEs and resistive internal kink modes [38][39][40].…”

Section: Physical Model and Simulation Setupmentioning

confidence: 99%

Simulation of non-resonant high-order harmonics energetic particle modes in tokamak plasmas

Liu,

Ren,

Yang

et al. 2024

Phys. Scr.

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Based on the parameters of the HL-2A experiment, the effect of energetic particles (EPs) on non-resonant high-order harmonics energetic particle modes (EPMs) with qmin>1 is investigated in the present work. Hybrid kinetic-magnetohydrodynamic nonlinear code M3D-K is performed to simulate the linear properties and the nonlinear evolution of the non-resonant EPM during neutral beam injection (NBI). To deeply understand the physical mechanism of interaction resonant between energetic-ions and non-resonant EPM, this work compares the effects of passing energetic particles and trapped energetic particles on the non-resonant EPM instabilities. It is numerically identified that EPs’ effects on high n harmonics (m/n = 2/2, 3/3, 4/4) instability are more obvious than the m/n = 1/1 mode. Furthermore, the effects of energetic particles injection energy, the minimum safety factor qmin , toroidal rotation and beam ion distribution on the features of high n harmonics are also investigated specifically. Toroidal rotation is found to suppress high n harmonics, which is more obvious for the modes driven by trapped particles. Nonlinear simulation results show that these non-resonant high n harmonics can induce larger energetic ion transport, which may affect the plasma confinement performance.

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“…型 [26] , 模型中跟踪了磁约束聚变等离子体的非线性演化, 主要包括模幅度和快粒子分布函数的非线性自洽演化, 采用完整的电阻磁流体方程来表述背景等离子体和漂移动理学方程来描述快粒子效应. 中许多重要的物理现象, 例如快粒子激发的环向阿尔芬本征模 [27] 以及环向阿尔芬本征模雪崩 [28] 、长寿模 [29] 、锯齿模 [30] 、鱼骨模 [31,32] 、比压阿尔芬本征模 [33] 、阿尔芬级联模 [34,35] 、鱼骨模与内部输运垒的相互作用 [36] 等.…”

Section: 数值模型和参数设置unclassified

Hybrid numerical simulation on fast particle transport induced by synergistic interaction of low- and medium-frequency magnetohydrodynamic instabilities in tokamak plasma

Zhu¹,

Chen²,

Feng³

et al. 2023

Acta Phys. Sin.

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In tokamak experiments, various MHD instabilities usually co-exist and interact with fast particles. It can cause significant fast particle transport and loss, and pose damage to the first wall, leading to discharge quench in tokamak. Therefore, understanding the physical mechanism of fast particle transport caused by MHD instabilities is a crucial but urgently solved physical issue for the steady-state long pulse operation of future reactor-graded devices. Based on the experimental phenomenon of synergy between nonresonant internal kink mode and tearing mode observed on NSTX, a spherical tokamak device, this paper utilizes the global nonlinear hybrid-kinetic simulation code M3D-K to compare the characteristics of fast particle loss, transport and redistribution in the two cases: I) only non-resonant internal kink modes; II) the synergy between the non-resonant internal kink mode and tearing mode. The physical mechanism of fast particle transport, loss and redistribution caused by such synergy is studied. The results show that the synergy between the non-resonant internal kink mode and the tearing mode can significantly enhance the loss and transport of fast particles. The main reason is that such synergy can provide a radial channel for fast particles to mitigate from the plasma core to the plasma boundary accompanied with the total stochasticity of the magnetic topology. These results can help understand the physical mechanism of the transport and loss of fast particles caused by the synergy of low-frequency MHD instabilities in future fusion reactors, and provide some new ideas for finding strategies to control and mitigate the loss and transport level of fast particles in future fusion reactors.

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Multiple interactions between fishbone instabilities and internal transport barriers in EAST plasmas

Cited by 9 publications

References 71 publications

Saturation of fishbone instability by self-generated zonal flows in tokamak plasmas

Saturation of fishbone instability by self-generated zonal flows in tokamak plasmas

Simulation of non-resonant high-order harmonics energetic particle modes in tokamak plasmas

Hybrid numerical simulation on fast particle transport induced by synergistic interaction of low- and medium-frequency magnetohydrodynamic instabilities in tokamak plasma

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