Bayesian optimization of massive material injection for disruption mitigation in tokamaks
Journal article, 2023

A Bayesian optimization framework is used to investigate scenarios for disruptions mitigated with combined deuterium and neon injection in ITER. The optimization cost function takes into account limits on the maximum runaway current, the transported fraction of the heat loss and the current quench time. The aim is to explore the dependence of the cost function on injected densities, and provide insights into the behaviour of the disruption dynamics for representative scenarios. The simulations are conducted using the numerical framework Dream (Disruption Runaway Electron Analysis Model). We show that, irrespective of the quantities of the material deposition, multi-megaampere runaway currents will be produced in the deuterium-tritium phase of operations, even in the optimal scenarios. However, the severity of the outcome can be influenced by tailoring the radial profile of the injected material; in particular, if the injected neon is deposited at the edge region it leads to a significant reduction of both the final runaway current and the transported heat losses. The Bayesian approach allows us to map the parameter space efficiently, with more accuracy in favourable parameter regions, thereby providing us with information about the robustness of the optima.

runaway electrons

fusion plasma

plasma simulation

Author

Istvan Pusztai

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

Ida Ekmark

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

H. Bergström

Max Planck Society

Student at Chalmers

P. Halldestam

Student at Chalmers

Max Planck Society

Patrik Jansson

Chalmers, Computer Science and Engineering (Chalmers), Functional Programming

M. Hoppe

Swiss Federal Institute of Technology in Lausanne (EPFL)

Oskar Vallhagen

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

Tünde-Maria Fülöp

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

Journal of Plasma Physics

0022-3778 (ISSN) 1469-7807 (eISSN)

Vol. 89 2 905890204

Implementation of activities described in the Roadmap to Fusion during Horizon Europe through a joint programme of the members of the EUROfusion consortium

European Commission (EC) (101052200), 2021-01-01 -- 2025-12-31.

Runaway electrons in fusion plasmas

Swedish Research Council (VR) (2018-03911), 2018-12-01 -- 2021-12-31.

Subject Categories

Computational Mathematics

Other Physics Topics

Fusion, Plasma and Space Physics

DOI

10.1017/S0022377823000193

More information

Latest update

4/17/2023