Speaker: Leonard-Petru Turica, University of Oxford, UK- Chaired by: Tunde Fulop, Associate Editor, JPP
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Date/Time: Thursday 09th October 2025, 4PM BST/11AM EDT
Title: Reconstructions of electron-temperature profiles from EUROfusion Pedestal Database using turbulence models and machine learning
Abstract: In magnetic confinement devices, the H-mode results in improved confinement and is therefore a desirable regime for future tokamaks. We focus on the anomalous heat transport governed by large electron-temperature and density gradients in the H-mode pedestals of JET-ILW. Using the EUROfusion Pedestal Database, we apply machine-learning (ML) methods to identify a hierarchy of the most important experimental parameters for reconstructing the electron-temperature pedestal. The success of our ML reconstructions suggests that the dataset is sufficiently large for statistically meaningful inference, and we recover a potential upper bound on the accuracy achievable with data-driven models. We then employ a physically informed model based on the electron-gradient ratio $\eta_e = L_{n_e} / L_{T_e}$ (a parameter relevant to the slab-ETG instability) and reconstruct pedestals using the experimental observation that $\eta_e \approx 2$ in much of the steep-gradient region. Another tested scaling law, $R/L_{T_e} = A (R/L_{n_e})^\alpha$, reveals a collapse of $A$ and $\alpha$ to a one-parameter family, enabling a compact empirical description of both JET-ILW and JET-C pedestals; the origin of this constraint remains unclear but may be linked to turbulent transport. Finally, we introduce the turbulent electron heat flux as a predictive parameter and test the accuracy of transport models inspired by nonlinear gyrokinetic simulations. Although these models vastly improve our previous analytic-modelling attempts, they underperform relative to ML methods; nevertheless, they offer a qualitative picture of the features required for turbulence models to represent the data and provide a foundation for future model validation against this database.
Speaker: Uddipan Banik, Institute for Advanced Study, Princeton- Chaired by: Dmitri Uzdensky, Associate Editor, JPP
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Date/Time: Thursday 16th October 2025, 4PM BST/11AM EDT
Title: TBC
Abstract: TBC.
Speaker: Alan Kaptanoglu, New York University, USA- Chaired by: Nuno Loureiro, Editor, JPP
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Date/Time: Thursday 23rd October 2025, 4PM BST/11AM EDT
Title: TBC
Abstract: TBC.
Speaker: Luca Orusa, Princeton University and Columbia University in New York City, USA- Chaired by: Antoine C Bret, Associate Editor, JPP
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Date/Time: Thursday 30th October 2025, 3PM GMT/11AM EDT
Title: TBC
Abstract: TBC.
Speaker: Lorenzo-Maria Perrone, Leibniz Institute for Astrophysics Potsdam, Germany- Chaired by: Francesco Califano, Associate Editor, JPP
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Date/Time: Thursday 6th November 2025, 4PM GMT/11AM EST
Title: TBC
Abstract: TBC.
Speaker: Tommaso Barberis, Princeton University, USA- Chaired by: Alex Schekochihin, Editor, JPP
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Date/Time: Thursday 13th November 2025, 4PM GMT/11AM EST
Title: TBC
Abstract: TBC.