| 1. |
- Skyman, Andreas, 1982, et al.
(författare)
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Particle transport in ion and electron scale turbulence
- 2012
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Ingår i: Proceedings of 24th Fusion Energy Conference -- IAEA CN-197.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This work deals with transport of main ions and impurities in micro turbulence driven by ion and electron temperature gradients, and trapped electrons. Results are obtained for both non- and quasi-linear simulations, using the gyrokinetic code GENE. Transport properties are quantified by the gradient of zero particle flux for steady state in source free regions.Results are compared with results obtained using a computationally efficient fluid model. Of particular interest are conditions of steep gradients, relevant to eg. transport barriers. Results from s–α geometry are compared with results with a JET-like magnetic equilibrium, and the effects on transport investigated. Further, the quality of He ash removal is studied.
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| 2. |
- Skyman, Andreas, 1982, et al.
(författare)
-
Particle transport in ion and electron scale turbulence
- 2012
-
Ingår i: Proceedings of 24th Fusion Energy Conference -- IAEA CN-197.
-
Konferensbidrag (refereegranskat)abstract
- Micro turbulent modes have important and non-trivial effects on transport in tokamaks. This paper deals with transport of main ions and impurities in ion and electron scale turbulence, driven by ion and electron temperature gradients, and trapped electrons. Using the gyrokinetic Vlasov code GENE, results are obtained from both nonlinear and quasi-linear simulations. The transport properties are quantified by calculating the gradient of zero particle flux for steady state in source free regions of the plasma. The results are compared and contrasted with results obtained using a computationally efficient fluid model.Of particular interest are conditions of steep gradients, relevant to e.g. transport barrier conditions. Further, results from a simple s–α geometry are compared with results obtained using a JET-like magnetic equilibrium, and the effects on transport investigated.
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| 3. |
- Skyman, Andreas, 1982, et al.
(författare)
-
Turbulent particle transport driven by ion and electron modes
- 2012
-
Ingår i: EPS 2012.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The topic of this work is turbulent transport of main ionsand impurities driven by ion (ITG) and electron modes (TE and electron scale ETG) in tokamaks. Regions relevant to the pedestal of H-mode plasmas (i.e. steep density gradients) are of particular interest. Using the code GENE, quasilinear (QL) and nonlinear (NL) gyrokinetic simulations are performed. Results are compared with a computation ally efficient fluid model.Transport is quantified by the density gradient of zero particle flux, related to the balance of convection and diffusion. This measure of the impurity peaking is calculated for ITG and TE mode turbulence, and conditions for zero main ion flux is investigated for ETG. Further, the quality of He ash removal is studied.
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| 4. |
- Skyman, Andreas, 1982, et al.
(författare)
-
Turbulent particle transport driven by ion and electron modes
- 2012
-
Ingår i: Proceedings of EPS 2012, Europhysics Conference Abstracts. - 2914771797 ; 36F, s. P5.033-
-
Konferensbidrag (refereegranskat)abstract
- The topic of the present work is the turbulent transport of main ions and impurities driven by ion modes (ITG) and electron modes (TE and electron scale ETG). Particle transport in regions relevant to the pedestal region of H-mode plasmas, i.e. with steep density gradients, are of particular interest. Using the code GENE, quasi- and nonlinear gyrokinetic simulations are performed, and the results are compared with a computationally efficient fluid model.The transport properties are quantified by locally finding density gradients (R/Ln ) yielding zero particle flux, which are directly related to the balance of convective and diffusive transport.This measure of the impurity peaking is calculated for ITG and TE mode turbulence in source-free regions of the plasma, and scalings are obtained for the driving gradients and the impurity charge number (Z). Further, the quality of the helium ash removal is studied for ITG and TE mode drive turbulence. For ETG modes, the focus is on the main ion transport, and the density gradient leading to zero main ion particle flux, related to the formation and sustainment of the edge pedestal, is estimated.
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