First numerical analysis of runaway electron generation in tungsten-rich plasmas towards ITER
Artikel i vetenskaplig tidskrift, 2024

The disruption and runaway electron analysis model code was extended to include tungsten impurities in disruption simulations with the aim of studying the runaway electron (RE) generation. This study investigates RE current sensitivity on the following plasma parameters and modelling choices: tungsten concentration, magnetic perturbation strength, electron modelling, thermal quench time and tokamak geometry—ITER-like or ASDEX-like. Our investigation shows that a tungsten concentration below 10−3 does not cause significant RE generation on its own. However, at higher concentrations it is possible to reach a very high RE current. Out of the two tested models of electrons in plasma: fluid and isotropic (kinetic), results from the fluid model are more conservative, which is useful when it comes to safety analysis. However, these results are overly pessimistic when compared to the isotropic model, which is based on a more reliable approach. Our results also show that the hot-tail RE generation mechanism is dominant as a primary source of RE in tungsten induced disruptions, usually providing orders of magnitude higher RE seed than Dreicer generation. We discuss best practices for simulations with tungsten-rich plasma, present the dependence of the safety limits on modelling choices and highlight the biggest shortcoming of the current simulation techniques. The obtained results pave the way for a wider analysis of tungsten impact on the disruption dynamics, including the mitigation techniques for ITER in the case of strong contamination of the plasma with tungsten.

ITER

computational plasma physics

tungsten impurities

runaway electrons

Författare

J. Walkowiak

Polish Academy of Sciences

Narodowe Centrum Badań Jądrowych

M. Hoppe

Kungliga Tekniska Högskolan (KTH)

Ida Ekmark

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

A. Jardin

Polish Academy of Sciences

J. Bielecki

Polish Academy of Sciences

K. Król

Polish Academy of Sciences

Y. Savoye-Peysson

Le Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA)

D. Mazon

Le Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA)

D. Dworak

Polish Academy of Sciences

M. Scholz

Polish Academy of Sciences

Nuclear Fusion

0029-5515 (ISSN) 1741-4326 (eISSN)

Vol. 64 3 036024

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

Europeiska kommissionen (EU) (101052200), 2021-01-01 -- 2025-12-31.

Ämneskategorier

Fusion, plasma och rymdfysik

DOI

10.1088/1741-4326/ad24a0

Mer information

Senast uppdaterat

2024-02-23