Modeling the complete prevention of disruption-generated runaway electron beam formation with a passive 3D coil in SPARC

TL;DR

This paper demonstrates through advanced modeling that a passive 3D coil can effectively prevent runaway electron beam formation during disruptions in the SPARC tokamak, enhancing its safety and reliability for fusion energy.

Contribution

It introduces a novel passive 3D coil design that passively prevents runaway electron beams during disruptions in the SPARC tokamak, a significant advancement over previous active mitigation methods.

Findings

Passive 3D coil prevents RE beam formation during disruptions.

Modeling shows effective mitigation in high-field, high-current tokamak.

Supports safer operation of SPARC for fusion energy development.

Abstract

The potential formation of multi-mega-ampere beams of relativistic "runaway" electrons (REs) during sudden terminations of tokamak plasmas poses a significant challenge to the tokamak's development as a fusion energy source. Here, we use state-of-the-art modeling of disruption magnetohydrodynamics coupled with a self-consistent evolution of RE generation and transport to show that a non-axisymmetric in-vessel coil will passively prevent RE beam formation during disruptions in the SPARC tokamak, a compact, high-field, high-current device capable of achieving a fusion gain Q > 2 in deuterium-tritium plasmas.