<i>E</i> × <i>B</i> flow shear mitigates ballooning-driven edge-localized modes at high collisionality: experiment and simulation

Kong, Defeng; Xu, X. Q.; Diamond, P. H.; Chen, J.G.; Huang, Chongxiang; Lan, Tao; Gao, Xiang; Li, J.G.; Team, East

doi:10.1088/1741-4326/aaef0c

Cited by 8 publications

(4 citation statements)

References 29 publications

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“…The theoretical works predict that E r × B shear can affect the magnitude and evolution of the cross phase of the velocity and pressure fluctuations in the peeling-ballooningmode-driven heat flux [31]. By using the specific co-NBI and ctr-NBI systems on EAST, an alternating E r × B flow shear discharge has been performed to study the impact of the E r × B flow shear on ballooning-driven ELM at a fixed high collisionallity (ν * = 2.3) [32]. The collisionallity was kept the same by the density feedback with the super molecular beam injection (SMBI) and well matching of the injecting power of co-NBI and ctr-NBI.…”

Section: Impact Of the E R × B Flow Shear On Ballooning-driven Elmmentioning

confidence: 99%

Recent advances in EAST physics experiments in support of steady-state operation for ITER and CFETR

et al. 2019

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The recent EAST experimental progress since the last IAEA FEC in 2016 is presented. First demonstration of >100 seconds time scale long-pulse steady-state scenario with a good plasma performance (H98(y2) ~ 1.1) and a good control of impurity and heat exhaust with the tungsten divertor has been successfully achieved on EAST using the pure RF power heating and current drive. The extended operation regimes have been obtained (βP~2.5 & βN~1.9 of using RF&NB and βP~1.9 & βN~1.5). High bootstrap current fraction up to 47% was achieved with q95~6.0-7.0. The interaction effect between the ECH and two LHW systems has been investigated for enhanced current drive and improved confinement quality. ELM suppression using the n= 2 RMPs has been achieved at q95 (≈ 3.2-3.7) with standard type-I ELMy H-mode operational window in EAST. Reduction of the peak heat flux on the divertor was demonstrated using the active radiation feedback control. An increase in the total heating power and improvement of the plasma confinement are expected using a 0-D model prediction for higher bootstrap fraction. Towards long pulse, high bootstrap current fraction operation, a new lower ITER-like tungsten divertor with active watercooling will be installed, together with further increase and improvement of heating and current drive capability.

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Section: Impact Of the E R × B Flow Shear On Ballooning-driven Elmmentioning

confidence: 99%

Recent advances in EAST physics experiments in support of steady-state operation for ITER and CFETR

et al. 2019

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“…To verify the theory that Er × B shear can affect the magnitude and evolution of the cross phase of the velocity and pressure fluctuations in the peeling-ballooning mode-driven heat flux, an alternating Er × B flow shear discharge was performed using the specific co-NBI and ctr-NBI systems in the EAST. The new results 50 show that the increased Er × B flow shear can significantly mitigate the ELM or even totally suppress the ELM when the shear is large enough. Simulations with BOUT++ support the observations made in the EAST, which indicates that the increased Er × B can reduce the linear growth rate of the ballooning mode and shorten its growth time (phase coherence time [PCT]).…”

Section: The East Project and Related Activitiesmentioning

confidence: 79%

Recent progress in Chinese fusion research based on superconducting tokamak configuration

et al. 2022

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“…By using the Doppler reflectometer, the edge radial electric fields produced by NBIs on the EAST were about 2 kV m −1 for 1 MW co-current NBI case and 6 kV m −1 for 1 MW counter-current NBI case [36,37]. Note that in our model, the beam injection power is 2 MW.…”

Section: The Radial Electric Field Produced By Nbimentioning

confidence: 83%

Simulations of the radial electric field induced by neutral beam injection in a tokamak

Xu¹,

Xu²,

Zhang³

et al. 2021

Nucl. Fusion

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A model based on Poisson’s equation has been proposed to study the radial electric field induced by neutral beam injection (NBI). The radial electric field is produced by charge separation of beam induced electrons and beam ions. The charge separation is produced by redistribution and loss of NBI ions, which is due to the magnetic drift and collision effects. The birth and steady-state distributions of NBI fast ions related to charge separation were numerically computed by the orbit code GYCAVA and the NBI code TGCO. According to our model, the neoclassical polarization density of bulk ions has a great shielding effect on the radial electric field due to charge separation. The simulation results show that NBI ions can produce a significant radial electric field (∼10 kV m−1) in the core region. The counter-current NBI (injection anti-parallel to the plasma current) can produce a negative radial electric field, which is due to the magnetic drift and collision effects of NBI ions. While the co-current injection (injection parallel to the plasma current) produces a positive radial electric field in the core region, which is mainly related to the magnetic drift of NBI ions. The dependence of the radial electric field on the injection direction and the beam energy of NBI has been investigated. As the beam energy increases, the magnitudes of the electric field for counter-injections increase and the magnitude of the electric field for co-current perpendicular injection decrease.

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E × B flow shear mitigates ballooning-driven edge-localized modes at high collisionality: experiment and simulation

Cited by 8 publications

References 29 publications

Recent advances in EAST physics experiments in support of steady-state operation for ITER and CFETR

Recent advances in EAST physics experiments in support of steady-state operation for ITER and CFETR

Recent progress in Chinese fusion research based on superconducting tokamak configuration

Simulations of the radial electric field induced by neutral beam injection in a tokamak

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