Dependence of the resonant magnetic perturbation penetration threshold on plasma parameters and ions in helical plasmas

Watanabe, K. Y.; Sakakibara, S.; Narushima, Y.; Ohdachi, S.; Suzuki, Y.; Takemura, Y.; Ida, K.; Yoshinuma, M.; Yamada, I.

doi:10.1088/1741-4326/ab2281

Cited by 3 publications

(3 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Plasma rotation is proven to play a critical role in the field penetration process due to the skin effect and the MHD stabilization effect [17,23]. Researches in TEXTOR and LHD exhibited that the field penetration threshold was strongly related to the slip frequency (frequency difference of perturbed field and MHD mode) [24][25][26]. Results in JET took the plasma rotation (ω 0 ) into account in the empirical scaling as…”

mentioning

confidence: 99%

Disentanglement of density and rotation dependences of the field penetration threshold on the J-TEXT tokamak

Huang

Liang

et al. 2020

Nucl. Fusion

View full text Add to dashboard Cite

The field penetration threshold of magnetic perturbations has been observed to vary non-monotonically with an increase of density in ohmic plasmas on the J-TEXT tokamak. This observation appears contradicting the previous empirical density scaling law. Disentanglement of plasma density and rotation dependences of the field penetration threshold has been carried out. It shows that the field penetration threshold depends only weakly on the density but linearly on the plasma rotation. This result is not only important for the prediction of error field tolerance in fusion devices, but also opens a question on the role of density in the forced magnetic reconnection process in magnetized plasmas.

show abstract

mentioning

confidence: 99%

Disentanglement of density and rotation dependences of the field penetration threshold on the J-TEXT tokamak

Huang

Liang

et al. 2020

Nucl. Fusion

View full text Add to dashboard Cite

show abstract

“…As the first step, in this study, we focus on the amplitude of the external RMP to completely suppress the instability. On the parameter dependence study of the RMP penetration threshold in the LHD, there are other works [13,16]. On the parameter dependence study of the complete suppression of the instability, with the shielding of the external RMP, is one of the future subjects.…”

Section: Dependence Of the Interchange Instability Response To The Ex...mentioning

confidence: 98%

“…So, we recognize a flattening of the electron temperature as a state of the external RMP penetration. Moreover, a flattening of the electron temperature is evaluated from the pressure gradient, because a sudden decrease of the pressure gradient and beta is observed due to the external RMP penetration [12,13]. Then, we mainly focus on the change of pressure gradient in this paper.…”

Section: Experimental Set-upmentioning

confidence: 99%

Suppression of resistive interchange instability by external RMP

et al. 2023

Self Cite

View full text Add to dashboard Cite

We experimentally investigate the effect of external resonant magnetic perturbation (RMP) on resistive interchange MHD instability which is typically observed in the Large Helical Device (LHD). We apply the m/n=1/1 external RMP to discharges with the m/n=1/1 interchange instability. We find that the electron density fluctuation as well as the magnetic field one is clearly reduced without a reduction of the pressure gradient by imposing the external RMP. Moreover, the achieved beta value as well as the beta gradient at the resonant surface is a little improved under certain conditions. Next, we investigate the responses of interchange instability to the external RMP under some different operational conditions. We find that the amplitude of the external RMP to completely suppress the instability with the shielding of the external RMP has a higher correlation with the volume-averaged beta value than other plasma parameters.

show abstract

Fast ion confinement in the presence of core magnetic islands in Wendelstein 7-X

Lazerson,

Geiger,

Kulla

et al. 2024

Plasma Phys. Control. Fusion

View full text Add to dashboard Cite

The eﬀect of magnetic islands in the core region of Wendelstein 7-X (W7-X) on fast ion conﬁnement is explored through simulations with the BEAMS3D code. A magnetic conﬁguration where the n/m = 5/5 island chain is shifted to r/a ∼ 0.7 allows the exploration of core island physics in W7-X. The control coil system on W7-X allows the tuning of the island size either increasing the island width or decreasing it. A coupling of the BEAMS3D code to the FIELDLINES code provides a versatile mechanism for incorporating magnetic islands and stochastic regions into the BEAMS3D code. Collisionless simulations suggest that the presence of core islands degrade the conﬁnement of passing particles in the region of the island chain. Full neutral beam simulations of W7-X show a similar behavior with conﬁnement decreasing as the island width is increased. Comparisons between a vacuum magnetic ﬁeld and low beta HINT2 simulation are made showing similar fast ion behavior. Measurements of lost fast ions in W7-X conﬁrm this trend with the control coil suppressed island conﬁguration showing lower losses than that with no control coils applied. Simulations of fast ion wall loads are performed suggesting no drastic change in loss pattern and a slight reduction in losses with minimized islands.

show abstract

Dependence of the resonant magnetic perturbation penetration threshold on plasma parameters and ions in helical plasmas

Cited by 3 publications

References 28 publications

Disentanglement of density and rotation dependences of the field penetration threshold on the J-TEXT tokamak

Disentanglement of density and rotation dependences of the field penetration threshold on the J-TEXT tokamak

Suppression of resistive interchange instability by external RMP

Fast ion confinement in the presence of core magnetic islands in Wendelstein 7-X

Contact Info

Product

Resources

About