Impacts of resonant magnetic perturbations on edge carbon transport and emission on EAST with EMC3-EIRENE modelling

The modelling of edge carbon transport and emission on EAST tokamak under resonant magnetic perturbation (RMP) fields has been conducted with the three-dimensional edge transport code EMC3-EIRENE. The measured vertical distribution of CVI emission by the extreme ultraviolet spectrometer system for the perturbed case shows a reduction in the CVI emission by 20 % compared to the equilibrium case. The chord-integrated CVI emission can be reconstructed by EMC3-EIRENE modelling, which presents an increase in the CVI emission with RMP fields. The discrepancy between experiments and simulations has been investigated by parameter study to examine the sensitivity of the simulation results on the edge plasma conditions and the impurity perpendicular transport. It is found that the variation of edge plasma conditions for the equilibrium case cannot resolve the discrepancy in the CVI emission between simulations and measurements. The simulations with enhanced impurity perpendicular transport coefficient allows a reasonable agreement with the measured reduction of CVI emission.

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Impact of screening of resonant magnetic perturbations in three dimensional edge plasma transport simulations for DIII-D

Physics of Plasmas ◽

10.1063/1.4714616 ◽

2012 ◽

Vol 19 (5) ◽

pp. 052507 ◽

Cited By ~ 24

Author(s):

H. Frerichs ◽

D. Reiter ◽

O. Schmitz ◽

P. Cahyna ◽

T. E. Evans ◽

...

Keyword(s):

Three Dimensional ◽

Edge Plasma ◽

Plasma Transport ◽

Magnetic Perturbations ◽

Resonant Magnetic Perturbations

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Experimental and simulation study of impurity transport response to RMPs in RF-heated H-mode plasmas at EAST

Journal of Plasma Physics ◽

10.1017/s0022377821000222 ◽

2021 ◽

Vol 87 (2) ◽

Author(s):

Germán Vogel ◽

Hongming Zhang ◽

Yongcai Shen ◽

Shuyu Dai ◽

Youwen Sun ◽

...

Keyword(s):

Inner Core ◽

Extreme Ultraviolet ◽

Transport Coefficients ◽

Three Dimensional ◽

Line Emission ◽

Core Region ◽

Emission Mitigation ◽

One Dimensional ◽

Impurity Transport ◽

Transport Code

Spatial profiles of impurity emission measurements in the extreme ultraviolet (EUV) spectroscopic range in radiofrequency (RF)-heated discharges are combined with one-dimensional and three-dimensional transport simulations to study the effects of resonant magnetic perturbations (RMPs) on core impurity accumulation at EAST. The amount of impurity line emission mitigation by RMPs appears to be correlated with the ion Z for lithium, carbon, iron and tungsten monitored, i.e. stronger suppression of accumulation for heavier ions. The targeted effect on the most detrimental high-Z impurities suggests a possible advantage using RMPs for impurity control. Profiles of transport coefficients are calculated with the STRAHL one-dimensional impurity transport code, keeping $\nu /D$ fixed and using the measured spatial profiles of $\textrm{F}{\textrm{e}^{20 + }}$ , $\textrm{F}{\textrm{e}^{21 + }}$ and $\textrm{F}{\textrm{e}^{22 + }}$ to disentangle the transport coefficients. The iron diffusion coefficient ${D_{\textrm{Fe}}}$ increases from $1.0- 2.0\;{\textrm{m}^2}\;{\textrm{s}^{ - 1}}$ to $1.5- 3.0\;{\textrm{m}^2}\;{\textrm{s}^{ - 1}}$ from the core region to the edge region $(\rho \gt 0.5)$ after the onset of RMPs. Meanwhile, an inward pinch of iron convective velocity ${\nu _{\textrm{Fe}}}$ decreases in magnitude in the inner core region and increases significantly in the outer confined region, simultaneously contributing to preserving centrally peaked $\textrm{Fe}$ profiles and exhausting the impurities. The ${D_{\textrm{Fe}}}$ and ${\nu _{\textrm{Fe}}}$ variations lead to reduced impurity contents in the plasma. The three-dimensional edge impurity transport code EMC3-EIRENE was also applied for a case of RMP-mitigated high-Z accumulation at EAST and compared to that of low-Z carbon. The exhaust of ${\textrm{C}^{6 + }}$ toward the scrape-off layer accompanying an overall suppression of heavier ${\textrm{W}^{30 + }}$ is observed when using RMPs.

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