Non‐local heat flux application for scrape‐off layer plasma

Bufferand, Hugo; Ciraolo, Guido; Cintio, Pierfrancesco Di; Fedorczak, N.; Ghendrih, Ph.; Lepri, Stefano; Livi, Roberto; Marandet, Y.; Serre, Éric; Tamain, P.

doi:10.1002/ctpp.201700162

Cited by 3 publications

(4 citation statements)

References 9 publications

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“…In the formulae above, r j are the particles position vectors, and the notation | z means that one is taking (without loss of generality) the component of the vector A i parallel to the z axis of the simulation's coordinate system. For 2D systems, Equation reduces to

v_{j}^{'}

= u i + G φ , i · δ v j , where G φ , i is a 2D rotation matrix of an angle φ chosen according to relations; see Ref. .…”

Section: Kinetic Modelling Of Heat Transfermentioning

confidence: 99%

“…In order to overcome this issue, we have introduced (see again Ref. ) the following expression for the heat flux:

q_{italicNL, T} ((), x) = \overset{q_{NL} ((), x)}{true} + q_{italicBC, 0} \exp ((), - \frac{x}{λ}) + q_{italicBC, L_{∥}} \exp ((), \frac{x - L_{∥}}{λ}) .

…”

Section: Introductionmentioning

confidence: 97%

“…We have shown in Ref. that solving the equation ∂ x q NL ( x ) = S using this non‐local expression for the heat flux computation can lead to discontinuities in the temperature profile if the source term S is very localized in space, such as, for example, in the case of the interaction with the wall, and the collisionality takes medium and low values as it can happen in the SOL plasma of tokamaks. In order to overcome this issue, we have introduced (see again Ref.…”

Section: Introductionmentioning

confidence: 99%

“…In order to overcome this issue, we have introduced (see again Ref. 13) the following expression for the heat flux: This expression exhibits a first term describing the non-local heat flux computed from the continuous temperature gradient expression in the plasma. The two last terms represent the impact of the boundary condition in the heat flux and the effect that decays exponentially away from the wall.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Fluid and kinetic modelling for non‐local heat transport in magnetic fusion devices

Ciraolo

Bufferand

Cintio

et al. 2018

Contributions to Plasma Physics

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In order to improve the presently used ad hoc flux limiter treatment of parallel heat flux transport in edge plasma fluid codes, here, we consider a generalized version of the Fourier law implementing a non‐local kernel for the heat flux computation. The Bohm boundary condition at the wall is recovered, introducing a volumetric loss term representing the contribution of suprathermal particles to the energy out flux. As expected, this contribution is negligible in the strongly collisional regime, while it becomes more and more dominant for marginally and low‐collisional regimes. In the second part of the paper, we consider a kinetic approach where collisions are considered using the multi‐particle collision algorithm. Kinetic simulation results at medium and low collisionality are also reported.

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v_{j}^{'}

= u i + G φ , i · δ v j , where G φ , i is a 2D rotation matrix of an angle φ chosen according to relations; see Ref. .…”

Section: Kinetic Modelling Of Heat Transfermentioning

confidence: 99%

“…In order to overcome this issue, we have introduced (see again Ref. ) the following expression for the heat flux:

q_{italicNL, T} ((), x) = \overset{q_{NL} ((), x)}{true} + q_{italicBC, 0} \exp ((), - \frac{x}{λ}) + q_{italicBC, L_{∥}} \exp ((), \frac{x - L_{∥}}{λ}) .

…”

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Fluid and kinetic modelling for non‐local heat transport in magnetic fusion devices

Ciraolo

Bufferand

Cintio

et al. 2018

Contributions to Plasma Physics

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Estimation of impact of non‐local ion heat flux model on transport simulation for DEMO‐relevant scrape‐off layer plasma

Homma,

Hoshino,

Yamoto

et al. 2024

Contrib. Plasma Phys

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In a fusion DEMOnstration reactor (DEMO)‐relevant scrape‐off layer plasma (SOL), whose collisionality is lower than in the SOLs of present‐day tokamaks, kinetic effects are predicted to reduce the plasma heat conductivity along the magnetic field below the value obtained with the classical Spitzer–Harm model. As a part of ongoing efforts to improve the predictive capability of SOL heat transport calculations, we have implemented the non‐local heat flux model proposed by [Luciani, Mora and Virmont, Phys. Rev. Lett. 51 (1983) 1664–1667] (here referred to as the LMV model) in the integrated SOL–divertor simulation code SONIC in order to account for the kinetic effect on the heat conduction due to the parallel streaming of rapidly moving particles. Our transport simulations for the Japanese demonstration tokamak reactor concept, JA DEMO, show that the LMV model yields a significantly reduced ion parallel conductive heat flux density both on the low‐ and high‐field side of the upstream SOL. The heat flux obtained with the LMV model seems to be consistent with earlier kinetic simulations of tokamak ion transport. As a consequence of the reduced heat flux, a significant increase in the ion temperature and a decrease in the density have also been found over a broad area of the upstream SOL.

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The diffusion limit of ballistic transport in the scrape-off layer

et al. 2020

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At least in the far scrape-off layer of magnetically confined fusion plasmas transport is intermittent and non-diffusive as observed by the appearance of plasma filaments. Transport codes using effective diffusion coefficients are still the main workhorse investigating the scrape-off layer and divertor regions. An effective perpendicular diffusion coefficient for intermittent filamentary dominated perpendicular transport in the scrape-off layer is motivated by the telegraph equation, describing an exponentially decaying correlated random walk. On short time scales the telegraph equation describes ballistic transport of filamentary structures with a typical velocity u b and correlation time τ. In stationary conditions the corresponding diffusion coefficient is given by u 2 b τ. Since u b and τ can be determined experimentally it is proposed to use u 2 b τ as an input for modeling or for interpretation of perpendicular transport in the far scrape-off layer.

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Non‐local heat flux application for scrape‐off layer plasma

Cited by 3 publications

References 9 publications

Fluid and kinetic modelling for non‐local heat transport in magnetic fusion devices

Fluid and kinetic modelling for non‐local heat transport in magnetic fusion devices

Estimation of impact of non‐local ion heat flux model on transport simulation for DEMO‐relevant scrape‐off layer plasma

The diffusion limit of ballistic transport in the scrape-off layer

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