Tractable flux-driven temperature, density, and rotation profile evolution with the quasilinear gyrokinetic transport model QuaLiKiz

Abstract

Quasilinear turbulent transport models are a successful tool for prediction of core tokamak plasma profiles in many regimes. Their success hinges on the reproduction of local nonlinear gyrokinetic fluxes. We focus on significant progress in the quasilinear gyrokinetic transport model QuaLiKiz [C. Bourdelle et al. 2016 Plasma Phys. Control. Fusion 58 014036], which employs an approximated solution of the mode structures to significantly speed up computation time compared to full linear gyrokinetic solvers. Optimization of the dispersion relation solution algorithm within integrated modelling applications leads to flux calculations ×10 6−7 faster than local nonlinear simulations. This allows tractable simulation of flux-driven dynamic profile evolution including all transport channels: ion and electron heat, main particles, impurities, and momentum. Furthermore, QuaLiKiz now includes the impact of rotation and temperature anisotropy induced poloidal asymmetry on heavy impurity transport, important for W-transport applications. Application within the JETTO arXiv:1708.01224v2 [physics.plasm-ph] 7 Aug 2017Tractable flux-driven temperature, density, and rotation profile evolution with the quasilinear gyrokinetic tran integrated modelling code results in 1 s of JET plasma simulation within 10 hours using 10 CPUs. Simultaneous predictions of core density, temperature, and toroidal rotation profiles for both JET hybrid and baseline experiments are presented, covering both ion and electron turbulence scales. The simulations are successfully compared to measured profiles, with agreement mostly in the 5-25% range according to standard figures of merit. QuaLiKiz is now open source and available at www.qualikiz.com.Tractable flux-driven temperature, density, and rotation profile evolution with the quasilinear gyrokinetic tran

Growth rates of ITG modes in the presence of flow shear

“…Thus, this study indicates that nonlinear effects leading to a lack of justification of linear E ×B stabilization models is limited to cases with significant PVG impact. This is in line with findings from quasilinear transport modeling in integrated modeling, where including the E×B stabilization in the inner half-radius (where PVG is more important) leads to an overprediction of the E ×B turbulence suppression and the temperature and density profiles [28].…”

First principle integrated modeling of multi-channel transport including Tungsten in JET

“…The QuaLiKiz output fluxes (per m 2 ) are (circular) flux-surface-averaged, and the full flux surface area is used to calculate the total transport rates within JETTO. The effective diffusivities and heat conductivities calculated from these fluxes within QuaLiKiz are transformed into JETTO coordinates, using general geometry information from JETTO [16]. The impact of poloidal asymmetries for turbulent transport of heavy impurities is included, see a comparaison with GKW here [16].…”

“…Therefore there are empty regions in D turb,ef f that are not empty in RV turb,ef f , and since it is averaged over 0.1s, in some cases both D turb,ef f and RV turb,ef f can be incorporated. The impact of poloidal asymmetries on W turbulent transport is accounted for in QuaLiKiz based on [39], as described in [16]. The impact of centrifugal effects on the various components of the turbulent convection (thermodiffusion, rotodiffusion, pure convection) results of a complex compensation of the different components (see [39]) leading, in this case, to a reduced turbulent W transport in absence of rotation.…”

Predictions of core plasma performance for the SPARC tokamak

“…The development and validation of theory-based reduced models and integrated modelling frameworks in recent years (Kinsey et al 2011;Citrin et al 2017;Kim et al 2017;Meneghini et al 2017;Linder et al 2018;Rodriguez-Fernandez et al 2018;Angioni et al 2019;White 2019) have allowed physic-based simulations to also inform the design of SPARC during the early stages of its development. This paper presents results from both empirical scalings and integrated modelling simulations of SPARC plasmas, with a focus on evaluating fusion gain with theory-based models and assessing the sensitivity to plasma physics assumptions.…”