Causal impact of tearing mode on zonal flows and local turbulence in the edge of HL-2A plasmas

Xu, Jianqiang; Qu, Yaoru; Li, Jingchun; Lin, Zhihong; Dong, J. Q.; Peng, Xiaodong; Jiang, Min; Qu, Hongpeng; Huang, Z.; Wu, Na; Wang, Weice; Hao, G. Z.; Chen, Wei; Li, Jiquan; Xu, Min

doi:10.1088/1741-4326/ac7888

Cited by 5 publications

(5 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, experiments on the HL-2A tokamak have shown that the modulation effect of the MI on turbulence is limited to the inner region of the MI and there is a MI threshold for modulating the turbulence around w ∼ 4 cm [22], which is consistent with Fitzpatrick's theoretical predictions [23]. Most recently, the multi-scale interactions among macroscale TM, meso-scale geodesic acoustic mode (GAM) and small-scale turbulence are carried out in the edge plasma of the HL-2A tokamak using the causality analysis method and the effect of the MI width on the nonlinear coupling among turbulence, GAM and TMs is also reported [24,25].…”

Section: Introductionsupporting

confidence: 83%

Global gyrokinetic simulations of the impact of magnetic island on ion temperature gradient driven turbulence

et al. 2023

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

The effect of island width on the multi-scale interactions between magnetic island (MI) and ion temperature gradient (ITG) turbulence has been investigated based on the global gyrokinetic approach. It is found that the coupling between the island and turbulence is enhanced when the MI width (w) becomes larger. A vortex flow that is highly sensitive to the width of the magnetic island can be triggered, ultimately resulting in a potent shear flow and a consequent reduction in turbulent transport. The shearing rate induced by the vortex flow is minimum at the O-point while it is maximum at both of the two reconnection points of the island, i.e., the X-points, regardless of the island width. There exists a nonmonotonic relationship between zonal flow (ZF) amplitude and island width, showing that the ZF is partially suppressed by medium-sized MIs whereas enhanced in the case of large island. A larger MI can tremendously damage the ITG mode structure, resulting in higher turbulent transport at the X-point whereas a lower one at the O-point, respectively. Such phenomenon will be less distinct at very small island widths below w/a ~ 8%≈ 12ρi (a is the minor radius and ρi the ion gyroradius), where it shows that turbulence near the X-point is hardly affected although it is still suppressed inside the island. Furthermore, the influence of different island sizes on turbulence transport level is also discussed.

show abstract

Section: Introductionsupporting

confidence: 83%

Global gyrokinetic simulations of the impact of magnetic island on ion temperature gradient driven turbulence

et al. 2023

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

show abstract

“…Jingchun Li presented the experimental observation of the nonlinear interactions among turbulence, geodesic acoustic mode, and tearing mode in HL-2A edge plasmas. It is found that the nonlinear interaction between GAM and background turbulence decreases with the magnetic island width, while the interaction between the magnetic island and the density perturbation-associated turbulence increases [19]. A special observation is that magnetic island (MI) can significantly reduce turbulence levels, with a non-monotonic dependence of the suppression effect on MI width.…”

Section: Micro-turbulence and Transportmentioning

confidence: 98%

“…Jianqiang Xu et al investigated the characteristics of geodesic acoustic mode (GAM) and its causal impact on turbulent transport in deuterium (D) and hydrogen (H) dominated ohmic plasmas in the edge region of HL-2A tokamak utilizing the direct causality analysis method [19]. It is shown that the nonlinear coupling between GAM and ambient turbulence as well as the information transfer from the radial electric field fluctuation of GAM to the particle flux and turbulence energy is also shown to be larger in the deuterium regime in comparison with hydrogen, implying that the regulation of turbulent transport by GAM ZF in D plasma is stronger than that in H isotope.…”

Section: Micro-turbulence and Transportmentioning

confidence: 99%

“…Ming Xu presented the analysis results of the EAST experiment, and it is obtained that (1) the low-frequency modes can be divided into two categories, and the frequency of the modes will sweep up or hop up with the decrease of q min ; (2) the modulus of low-frequency mode is m/n = 4/2, 6/3, K; (3) the radial structure of low-frequency mode is characterized by 'spiral dart' structure; (4) the excitation conditions of the low-frequency modes on EAST are given in detail with the help of the numerical solution of GFLDR. In addition, the frequency sweep or hopping characteristics of such low-frequency modes strongly depend on the change of the q profile, so they can be used for MHD spectroscopy [37].…”

Section: Energetic Particle Physicsmentioning

confidence: 99%

See 1 more Smart Citation

Summary of the 10th Conference on Magnetically Confined Fusion Theory and Simulation (CMCFTS)

Wang

Qiu

Wang

et al. 2023

Plasma Sci. Technol.

View full text Add to dashboard Cite

This paper gives a summary of the organization and the presentations delivered at the 10th Conference on Magnetically Confined Fusion Theory and Simulation (CMCFTS) held in Zhuhai, China, from 28th to 31st October 2022. The conference focused on the latest progress in the research of the magnetic confined fusion plasma theory and simulations, as well as the large-scale numerical simulation techniques developed in recent years. This conference is held both online and offline, with about 110 domestic participants from 18 institutes participating in the live conference, and the statistical data from the live broadcast platform indicated that the online conference attracted over 20000 views per day. A summary of the conference is given, and the history of the CMCFTS is presented. A brief introduction to the poster section is also included in this paper.

show abstract

“…In order to further investigate the modulation relationship between QCMs and turbulence, the envelope analysis [46] is used to identify interaction between the QCMs and AT. The envelope based on the analytic signal approach consists of a real signal of finite energy which is Fourier transformable and band-limited and the Hilbert transform of the original real signal.…”

Section: Impact Of Qcms On Pedestal Turbulencementioning

confidence: 99%

Effects of inter-ELM quasi-coherent modes on the dynamics of pedestal turbulence on HL-2A tokamak

Wen,

Shi,

Zhong

et al. 2024

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

The role of a series of quasi-coherent modes (QCMs) on the turbulence properties has been investigated during Type-III ELMs under HL-2A high confinement mode (H-mode) scenarios. The QCMs are essentially electrostatic and appear during the inter-ELM periods, with a frequency ranging from 20 kHz to 60 kHz. These QCMs are localized in the pedestal region and are related to the saturation of density gradient in the pedestal. Nonlinear couplings between QCMs and ambient turbulence have been observed and also verified through the envelope modulation of turbulence in density by the radial electrical field fluctuation of the modes. The presence of QCMs can increase the radial and poloidal turbulence correlation lengths, thereby modulating the turbulent transport. Experimental results show that QCMs significantly impact pedestal turbulence and transport by increasing the correlation length as well as the decorrelation time of turbulent eddies. The flow shearing rate in pedestal region is also enhanced to a level that surpasses the decorrelation frequency of turbulence, thus, the existence of QCMs has the ability to put off the ELM burst due to relative stronger stabilization of turbulence by sheared flows. The above results have demonstrated that the pedestal dynamics is largely determined by the complex interactions among QCMs, turbulence and the shear flow.

show abstract

Causal impact of tearing mode on zonal flows and local turbulence in the edge of HL-2A plasmas

Cited by 5 publications

References 45 publications

Global gyrokinetic simulations of the impact of magnetic island on ion temperature gradient driven turbulence

Global gyrokinetic simulations of the impact of magnetic island on ion temperature gradient driven turbulence

Summary of the 10th Conference on Magnetically Confined Fusion Theory and Simulation (CMCFTS)

Effects of inter-ELM quasi-coherent modes on the dynamics of pedestal turbulence on HL-2A tokamak

Contact Info

Product

Resources

About