Full suppression of runaway electron generation by the mode penetration of resonant magnetic perturbations during disruptions on J-TEXT

Lin, Z.; Chen, Z Y; Huang, Dan; Huang, Junjie; Tong, R. H.; Wei, Yunong; Yan, Wei; Li, D; Hu, Qiming; Huang, Yuan; Yang, Hui; Li, Y; Zhang, X Q; Ren, Bo; Yang, Zhoujun; Gao, Li; Ding, Yonghua; Wang, Z J; Zhang, M; Liang, Yun-Feng; Pan, Yuan; Jiang, Zhonghe; Team, J-Text

doi:10.1088/1361-6587/aaf691

Cited by 18 publications

(24 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the MGI shutdown process, the external applied RMP field might play various roles, either enhancing [50] or suppressing [51] the RE production, depending on the RMP amplitude. Recent studies on J-TEXT reveal more features of the impact of RMP on MGI-triggered disruptions.…”

Section: Impact Of Rmp On Mgi-triggered Disruptionmentioning

confidence: 99%

Advances in physics and applications of 3D magnetic perturbations on the J-TEXT tokamak

Wang¹,

Liang²,

Ding³

et al. 2022

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

In the recent two years, three major achievements have been made on J-TEXT in supporting for the expanded operation regions and diagnostic capabilities, e.g. the 105 GHz/500 kW/1 s ECRH system and the poloidal divertor configuration. Especially, the 400 kW ECW has also been successfully injected into the diverted plasma. The locked mode (LM), especially the 2/1 LM, is one of the biggest threats to the plasma operation. Both the thresholds of 2/1 and 3/1 LM are observed to vary non-monotonically on electron density. The electrode biasing (EB) was applied successfully to unlock the LM from either a rotating or static RMP field. In the presence of 2/1 LM, three kinds of standing wave (SW) structures have been observed to share a similar connection to the island structure, i.e. the nodes of the SWs locate around the O- or X- points of the 2/1 island. The control and mitigation of disruption is essential to the safe operation of ITER, and it has been systematically studied by applying RMP field, MGI and SPI on J-TEXT. When the RMP induced 2/1 LM is larger than a critical width, the MGI shutdown process can be significantly influenced. If the phase difference between the O-point of LM and the MGI valve is +90° (or -90°), the penetration depth and the assimilation of impurities can be enhanced (or suppressed) during the pre-TQ phase and result in a faster (or slower) thermal quench. A secondary MGI can also suppress the RE generation, if the additional high-Z impurity gas arrives at the plasma edge before TQ. When the secondary MGI has been applied after the formation of RE current plateau, the RE current can be dissipated, and the dissipation rate increases with the injected impurity quantity, and saturates with a maximum of 28 MA/s.

show abstract

Section: Impact Of Rmp On Mgi-triggered Disruptionmentioning

confidence: 99%

Advances in physics and applications of 3D magnetic perturbations on the J-TEXT tokamak

Wang¹,

Liang²,

Ding³

et al. 2022

Nucl. Fusion

Self Cite

View full text Add to dashboard Cite

show abstract

“…The runaway current can be suppressed with mode locking by the application of m/n = 2/1 RMP fields before the TQ. [26] In the meantime, dominant multi-modes (such as 3/1 and 2/1 modes) of RMP are applied to suppress REs on J-TEXT. [27] Partial experiment results show that the phase and amplitude of the two modes have important influences on RE suppression, but unfortunately, the phase adjustment range of the J-TEXT between the two modes on RMP files is limited.…”

Section: Introductionmentioning

confidence: 99%

Effect of the relative phase between pre-existing 2/1 and 3/1 magnetic islands on the suppression of runaway electrons on J-TEXT

Xiong

Jiang²,

Jiao³

et al. 2023

Chinese Phys. B

View full text Add to dashboard Cite

In the experiments of actively triggering plasma disruption by massive gas injection, the externally applied resonant magnetic perturbation has been used to mitigate the hazard of runaway electron (RE). Motivated by the experiment of multimode coupling to suppress REs on J-TEXT, some typical simulation cases with NIMROD (Non-Ideal MHD with Rotation-Open Discussion) code are carried out to explore the influential mechanism of different relative phases between m/n = 2/1 and m/n = 3/1 magnetic islands on the confinement of REs. Results show that the RE confinement is drastically affected by the relative phase between 2/1 and 3/1 magnetic islands. When the “O point” phase of 2/1 and 3/1 magnetic islands is toroidal 330°, REs can be effectively lost. The fitting curve of the remaining ratio of REs vs. the relative toroidal phase is predicted to approximate a sine-like function dependence. Further studies indicate that the phase difference between coexisting 2/1 and 3/1 islands can affect the radial transport of impurities. The loss of runaway electrons is closely related to the deposition effect of impurity. The impurity is easier to spread into the core region with smaller poloidal phase difference between the radial velocity of impurity and the impurity quantity of Ar.

show abstract

“…The most studied mitigation method is massive material injection (gas or shattered pellet) either before or after RE beam formation [6][7][8][9]. RE avoidance has also been pursued via applied 3D magnetic fields, with the resulting stochasticity transporting REs out of the plasma [10][11][12][13][14][15][16][17]. While initial results are promising, fully stochastic fields have not yet been achieved [18,19], and this is still an active mitigation scheme.…”

Section: Introductionmentioning

confidence: 99%

Modeling the complete prevention of disruption-generated runaway electron beam formation with a passive 3D coil in SPARC

Tinguely

Izzo²,

Garnier

et al. 2021

Nucl. Fusion

View full text Add to dashboard Cite

The potential formation of multi-mega-ampere beams of relativistic ‘runaway’ electrons (REs) during sudden terminations of tokamak plasmas poses a significant challenge to the tokamak’s development as a fusion energy source. Here, we use state-of-the-art modeling of disruption magnetohydrodynamics coupled with a self-consistent evolution of RE generation and transport to show that a non-axisymmetric in-vessel coil will passively prevent RE beam formation during disruptions in the SPARC tokamak, a compact, high-field, high-current device capable of achieving a fusion gain Q > 2 in deuterium–tritium plasmas.

show abstract

Full suppression of runaway electron generation by the mode penetration of resonant magnetic perturbations during disruptions on J-TEXT

Cited by 18 publications

References 43 publications

Advances in physics and applications of 3D magnetic perturbations on the J-TEXT tokamak

Advances in physics and applications of 3D magnetic perturbations on the J-TEXT tokamak

Effect of the relative phase between pre-existing 2/1 and 3/1 magnetic islands on the suppression of runaway electrons on J-TEXT

Modeling the complete prevention of disruption-generated runaway electron beam formation with a passive 3D coil in SPARC

Contact Info

Product

Resources

About