Application of Gaussian process regression to plasma turbulent transport model validation via integrated modelling

A. Ho (Corresponding author), J. Citrin, F. Auriemma, C. Bourdelle, F.J. Casson, Hyun Tae Kim, P. Manas, G. Szepesi, H. Weisen

Onderzoeksoutput: Bijdrage aan tijdschriftTijdschriftartikelAcademicpeer review

7 Citaten (Scopus)

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This paper outlines an approach towards improved rigour in tokamak turbulence transport model validation within integrated modelling. Gaussian process regression (GPR) techniques were applied for profile fitting during the preparation of integrated modelling simulations allowing for rigourous sensitivity tests of prescribed initial and boundary conditions as both fit and derivative uncertainties are provided. This was demonstrated by a JETTO integrated modelling simulation of the JET ITER-like-wall H-mode baseline discharge #92436 with the QuaLiKiz quasilinear turbulent transport model, which is the subject of extrapolation towards a deuterium Ctritium plasma. The simulation simultaneously evaluates the time evolution of heat, particle, and momentum fluxes over ~10 confinement times, with a simulation boundary condition at ptor = 0.85. Routine inclusion of momentum transport prediction in multi-channel flux-driven transport modelling is not standard and is facilitated here by recent developments within the QuaLiKiz model. Excellent agreement was achieved between the fitted and simulated profiles for ne, Te, Ti, and Ωtor within 2σ, but the simulation underpredicts the mid-radius Ti and overpredicts the core ne and Te profiles for this discharge. Despite this, it was shown that this approach is capable of deriving reasonable inputs, including derivative quantities, to tokamak models from experimental data. Furthermore, multiple figures-of-merit were defined to quantitatively assess the agreement of integrated modelling predictions to experimental data within the GPR profile fitting framework.

Originele taal-2Engels
Artikelnummer056007
Pagina's (van-tot)1-18
Aantal pagina's18
TijdschriftNuclear Fusion
Volume59
Nummer van het tijdschrift5
DOI's
StatusGepubliceerd - 22 mrt 2019

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