Modeling runaway electron mitigation via passively driven plasma instabilities in a high-current tokamak
Abstract
A critical challenge for tokamak-based fusion power plants is the formation of high-current, relativistic runaway electron (RE) beams during abrupt confinement loss events called disruptions. RE beams may significantly damage machine components if left unmitigated, jeopardizing the operational and economic viability of fusion power plants. We present the first self-consistent extended magnetohydrodynamic (MHD) computational study of RE mitigation with a passively driven RE mitigation coil (REMC) in a high-current tokamak. RE generation and transport are coupled with REMC-driven MHD activity in a 3D simulation that models the thermal and current quench phases of a mid-plane disruption, together with the vertical displacement and final termination of the plasma and RE beam on SPARC -- a high-field, high-current tokamak designed to achieve a fusion gain Q > 1. We demonstrate that REMC-driven magnetic stochasticity can reduce the RE current by over an order-of-magnitude when compared to unmitigated disruptions. The final termination is mediated via a post-thermal-quench "cold" vertical displacement of the plasma, which, together with magnetic stochasticity, increases RE losses via scrape-off once the plasma contacts the first wall. These results demonstrate a viable mechanism for RE mitigation using passively driven plasma instabilities on high-current tokamaks.
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BibTeX
@misc{datta2026modeling,
title = {{Modeling runaway electron mitigation via passively driven plasma instabilities in a high-current tokamak}},
author = {R Datta and C Clauser and G Hu and A Braun and N Ferraro and R Sweeney and A Tinguely and},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.04906},
eprint = {2611.04906},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.04906},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Modeling runaway electron mitigation via passively driven plasma instabilities in a high-current tokamak
AU - R Datta
AU - C Clauser
AU - G Hu
AU - A Braun
AU - N Ferraro
AU - R Sweeney
AU - A Tinguely and
PY - 2026
DA - 2026/11/03
PB - arXiv
DO - 10.48550/arxiv.2611.04906
UR - https://arxiv.org/abs/2611.04906
AB - A critical challenge for tokamak-based fusion power plants is the formation of high-current, relativistic runaway electron (RE) beams during abrupt confinement loss events called disruptions. RE beams may significantly damage machine components if left unmitigated, jeopardizing the operational and economic viability of fusion power plants. We present the first self-consistent extended magnetohydrodynamic (MHD) computational study of RE mitigation with a passively driven RE mitigation coil (REMC) in a high-current tokamak. RE generation and transport are coupled with REMC-driven MHD activity in a 3D simulation that models the thermal and current quench phases of a mid-plane disruption, together with the vertical displacement and final termination of the plasma and RE beam on SPARC -- a high-field, high-current tokamak designed to achieve a fusion gain Q > 1. We demonstrate that REMC-driven magnetic stochasticity can reduce the RE current by over an order-of-magnitude when compared to unmitigated disruptions. The final termination is mediated via a post-thermal-quench "cold" vertical displacement of the plasma, which, together with magnetic stochasticity, increases RE losses via scrape-off once the plasma contacts the first wall. These results demonstrate a viable mechanism for RE mitigation using passively driven plasma instabilities on high-current tokamaks.
ER -