Abstract Details
Abstracts
Author: Leonhard A. Leppin
Requested Type: Poster
Submitted: 2025-03-12 17:01:55
Co-authors: C.Stephens, P.-Y.Li, N.M.Cao, C.Curry, T.Oliver, D.Hatch
Contact Info:
The University of Texas at Austin
201 E 24th St
Austin, TX 78712
USA
Abstract Text:
The overall confinement in tokamak H-modes strongly depends on properties of the pedestal. Predictions of pedestal profiles are currently limited by gaps in the modeling capability of pedestal transport. While high-fidelity gyrokinetic simulations of pedestal transport are computationally too expensive for routine application, state-of-the-art reduced pedestal models rely on transport constraints that limit their applicability in relevant plasma scenarios (e.g. ELM-free regimes). This work aims to narrow the gap in modeling capabilities by developing fast, validated transport models for the pedestal region. The transport models are based on a quasilinear mixing length approach, utilizing linear gyrokinetic (GK) simulations. When possible, free model parameters are tuned to match nonlinear GK simulations.
We report on progress developing an uncertainty quantification framework for pedestal predictions. The framework includes the quantification of transport model uncertainties using Bayesian calibration and model inadequacy tools. Experimental uncertainties are quantified using a Gaussian process regression ansatz. The forward propagation of model and experimental uncertainties to the pedestal profile predictions is implemented using the integrated modeling framework ASTRA. Initial results of a validation under uncertainty for two transport models (one based on electron temperature gradient (ETG) modes [Hatch et al., NF, 2024] and the other based on microtearing modes) are presented.
Characterization: 1.0
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