Toroidal modeling of plasma response to RMP fields for HL-2M

Hao, G. Z.; Li, C.Y.; Liu, Y.Q.; Chen, H.T.; Wang, S.; Bai, Xue; Dong, Guangsheng; He, Huimin; Zhao, Yifei; Miao, Yutian; Zhou, Lina; Xu, Jianqiang; Zhang, N.; Chen, Q.; Sun, Tengfei; Ji, X.Q.; Liu, Yi; Zhong, Weizhi; Xu, M.; Duan, X.R.

doi:10.1088/1741-4326/ac2ff6

Cited by 9 publications

(9 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We find that the normal displacement strongly peaks near the X-point, indicating that the RMP field induces a strong edge peeling response. This type of plasma response, associated with the n = 1 RMP in odd parity configuration in HL-2A, has been found to strongly facilitate ELM control in other devices [36][37][38][39] as well as in HL-2A [35].…”

Section: Linear Plasma Responsementioning

confidence: 83%

Toroidal modeling of plasma flow damping and density pump-out by RMP during ELM mitigation in HL-2A

Zhang

Liu

et al. 2023

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

Reduction of both the plasma density and toroidal flow speed, due to application of the predominantly n=1 (n is the toroidal mode number) resonant magnetic perturbation (RMP) for controlling the edge localized mode in the HL-2A tokamak, is numerically investigated utilizing the quasi-linear initial-value code MARS-Q (Liu et al 2013 Phys. Plasmas 20 042503). Simulation results reveal that the neoclassical toroidal viscosity (NTV) due to 3D fields plays the key role in modifying the plasma momentum and particle transport in the HL-2A discharge. By comparing the modeling results with the measured density pump-out in the experiment, the electron NTV particle flux model, in combination with the free-boundary condition for the axisymmetric change of the density at the plasma edge, is found to yield the best agreement in terms of both the pump-out level and the overall time scale. Further sensitivity studies show that the simulated density pump-out level is reasonably robust against variations in the model assumptions, including the particle diffusion model and the non-ambipolar versus ambipolar NTV particle flux. The latter however affects the time scale for reaching the steady state solution. Finally, it is found that the plasma edge-peeling response, the NTV torque, as well as the plasma momentum and particle transport, all are sensitive to the toroidal phase difference between the upper and lower rows of the RMP coil currents in HL-2A, with the 30 degrees coil phasing producing the minimal side effects on the plasma.

show abstract

Section: Linear Plasma Responsementioning

confidence: 83%

Toroidal modeling of plasma flow damping and density pump-out by RMP during ELM mitigation in HL-2A

Zhang

Liu

et al. 2023

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

show abstract

“…The parallel component of the perturbed velocity is taken along the equilibrium field line. The damping term does not play a significant role at low-beta (as in the work presented here), but it is essential for high-beta plasmas [30,31]. In this work it is fixed to κ ∥ = 1.5 for consistency with previous work on MAST [24].…”

Section: The Mars-f Modelmentioning

confidence: 88%

Chasing the multi-modal plasma response in MAST-U

Munaretto,

Liu,

Ryan

et al. 2024

Plasma Phys. Control. Fusion

Self Cite

View full text Add to dashboard Cite

Achieving ELM suppression in spherical tokamaks by applying resonant magnetic perturbations (RMP) has proven challenging. The poloidal spectrum of the applied RMP is a key parameter that has an impact on the capability to mitigate and eventually suppress ELMs. In this work the resistive magnetohydrodynamic (MHD) code MARS-F (Liu et al 2000 Phys. Plasmas 7 3681 ) is used to evaluate the possibility of directly measuring the plasma response in MAST-U, and particularly its variation as function of the applied poloidal spectrum, in order to guide the experimental validation of the predicted best RMP configuration for ELM suppression. Toroidal mode number n=2 RMP is considered to minimize the presence of sidebands, and to avoid the deleterious core coupling of n=1. Singular Value Decomposition is used to highlight linearly independent structures in the simulated magnetic 3D fields and how those structures can be measured at the wall where the magnetic sensors are located. Alternative ways to measure the multimodal plasma response and how they can be used to infer the best RMP configuration to achieve ELM suppression are also presented, including the plasma displacement and the 3D footprints at the divertor plates.

show abstract

“…It is demonstrated that the strong SWD plays an important role in high β N (e.g. β N >∼ 0.85β limit N ) plasma [64][65][66]. In this work, since β N = 1.7 is far below the Troyon no-wall beta limit (β limit N 2.9) for the n = 2 external kink instability, the weak SWD with κ = 0.1 is assumed.…”

Section: Modeling Approachmentioning

confidence: 94%

Toroidal modeling of 3D perturbations generated by current filaments in scrape-off layer in tokamak with biased divertor targets

et al. 2022

Self Cite

View full text Add to dashboard Cite

The divertor biasing technique offers a promising alternative to control the edge localized mode (ELM) as well as the divertor heat load in tokamaks, as compared to the resonant magnetic perturbation (RMP) generated by magnetic coils. The linear resistive MHD code MARS-F [Liu et al. Phys. Plasmas 7, 3681 (2000)] is employed to study the plasma response to the $n=2$ ($n$ is the toroidal mode number) field perturbation in HL-2A, produced by the divertor biasing current filaments flowing in the scrape-off layer (SOL) region. The response field due to biasing currents is compared with the RMP field utilized for ELM control in HL-2A. The strength of the radial resonant field perturbation, produced by the biasing currents of 100 A level, is found to be comparable with RMP generated by several kA of ELM control coil currents for the reference plasma. The plasma normal displacement near the X-point and {the associated neoclassical toroidal viscosity torque are} also computed to be similar between these two techniques. The modeling results thus strongly suggest that the biasing technique can be applied to control ELMs. Moreover, the biasing currents produce field perturbations, including the plasma response, that are localized more near the plasma edge (compared to the RMP counterpart), thus reducing the chance of mode locking associated with core perturbations. Particle orbit tracing also reveals that the biasing current produced magnetic perturbation tends to widen the heat deposition region and induce the strike point splitting of the ion saturation flow on the outer divertor surface, consistent with experimental observations in HL-2A. These toroidal modeling results confirm the possibility of ELM control and plasma exhaust solution by the divertor biasing technique.

show abstract

Toroidal modeling of plasma response to RMP fields for HL-2M

Cited by 9 publications

References 58 publications

Toroidal modeling of plasma flow damping and density pump-out by RMP during ELM mitigation in HL-2A

Toroidal modeling of plasma flow damping and density pump-out by RMP during ELM mitigation in HL-2A

Chasing the multi-modal plasma response in MAST-U

Toroidal modeling of 3D perturbations generated by current filaments in scrape-off layer in tokamak with biased divertor targets

Contact Info

Product

Resources

About