scholarly journals Reproduction of collector probe deposition profiles using the far-SOL impurity transport code 3DLIM

2020 ◽  
Vol 25 ◽  
pp. 100811
Author(s):  
S.A. Zamperini ◽  
J.D. Elder ◽  
P.C. Stangeby ◽  
J.H. Nichols ◽  
D.C. Donovan ◽  
...  
2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Germán Vogel ◽  
Hongming Zhang ◽  
Yongcai Shen ◽  
Shuyu Dai ◽  
Youwen Sun ◽  
...  

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.


2003 ◽  
Vol 313-316 ◽  
pp. 1183-1187 ◽  
Author(s):  
I. Hyodo ◽  
M. Hirano ◽  
K. Miyamoto ◽  
K. Hoshino ◽  
A. Hatayama

2008 ◽  
Vol 48 (1-3) ◽  
pp. 280-284 ◽  
Author(s):  
K. Hoshino ◽  
M. Noritake ◽  
M. Toma ◽  
A. Hatayama

2020 ◽  
Vol 248 ◽  
pp. 106979 ◽  
Author(s):  
Shohei Yamoto ◽  
Yuki Homma ◽  
Kazuo Hoshino ◽  
Mitsunori Toma ◽  
Akiyoshi Hatayama

Author(s):  
Colin K Swee ◽  
Benedikt Geiger ◽  
Ralph Dux ◽  
Santhosh Kumar ◽  
Fernando Castillo ◽  
...  

Abstract The transport of carbon impurities has been studied in the helically symmetric stellarator experiment (HSX) using active and passive charge exchange recombination spectroscopy (CHERS). For the analysis of the CHERS signals, the STRAHL impurity transport code has been re-written in the python programming language and optimized for the application in stellarators. In addition, neutral densities both along the NBI line of sight as well as for the background plasma have been calculated using the FIDASIM code. By using the basinhopping algorithm to minimize the difference between experimental and predicted active and passive signals, significant levels of impurity diffusion are observed. Comparisons with neoclassical calculations from DKES/PENTA show that the inferred levels exceed the neoclassical transport by about a factor of four in the core and more than 100 times towards the plasma edge, thus indicating a high level of anomalous transport. This observation is in agreement with experimental heat diffusivites determined from a power balance analysis which exhibit strong anomalous transport as well.


Author(s):  
Tatsuhiko Sato ◽  
Koji Niita ◽  
Norihiro Matsuda ◽  
Shintaro Hashimoto ◽  
Yosuke Iwamoto ◽  
...  

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