|approved||divertor_heat_flux_based_on_bout___and_solps.pdf||2016-02-16 00:05:16||Bin Chen|
Author: Bin Chen
Requested Type: Pre-Selected Invited
Submitted: 2016-02-16 00:01:04
Co-authors: X.Q.Xu, T.Y.Xia, B.LaBombard, J.W.Ahn, C.Lasnier,T.H.Osborne, M.Y.Ye
Lawrence Livermore National Laboratory
Livermore, California 94550
China Fusion Engineering Testing Reactor is under conceptual design, acting as a bridge between ITER and DEMO. SOLPS code package is a fundamental tool for the design of CFETR divertor and for predictive simulations. SOLPS uses 2D fluid plasma model, including multiple ions and charge states, and comprehensive atomic reaction rates (ionization, radiation, etc). The classical transport is assumed parallel to magnetic field, with ad-hoc transport coefficients in the cross-field direction. Although it is one of the standard edge codes, major uncertainty in SOLPS and other edge transport simulations is the anomalous perpendicular transport coefficients used (not from first principles).
In order to do consistent SOL plasma transport calculations, the 2D fluid code SOLPS has been externally coupled to the 3D turbulence code BOUT++ for DIII-D and C-Mod. The basis of this method is the use of file I/O transfer between the codes being coupled. The coupling procedure is described as follow. (1) BOUT++ turbulence simulations are first performed for DIII-D and C-Mod discharges to get saturated turbulent particle and heat fluxes using experimentally measured midplane plasma profiles inside separatrix; (2) Given plasma density and temperature almost at the separatrix as boundary conditions, and surface- and time-averaged turbulent fluxes in the SOL, the SOLPS simulations are performed to obtain a steady state SOL plasma profiles and heat fluxes at divertor plates; (3) Compare the midplane plasma profiles and divertor heat fluxes with experimental measurements; (4) The SOLPS SOL plasma profiles are then used for BOUT++ turbulence simulations to check the convergence for possible impact on turbulence spreading in the SOL; (5) Divertor gas puff and impurity injection will be performed in comparison with experimental divertor heat fluxes.
Nonlinear simulation results by BOUT++ shows a reasonable agreement of turbulent heat flux onto outer divertor target with experiment.
I have 2 figures in this abstract, where I attached a PDF, which is more completed. Thank you very much!