Magnetized ICF implosions: Non-axial magnetic field topologies

TL;DR

This paper investigates four magnetic field topologies for spherical inertial confinement fusion, finding that closed field lines significantly improve hot-spot performance and plasma properties, potentially enabling a fundamental redesign of capsule implosions.

Contribution

It introduces and compares four magnetic topologies, highlighting the superior performance of closed field lines in ICF implosions and their potential for fundamental redesign.

Findings

Closed field lines double ion temperature before alpha-heating

Electron temperatures exceed 100 keV with closed fields

Mirror fields enhance magnetization effects over axial fields

Abstract

This paper explores 4 different magnetic field topologies for application to spherical inertial confinement fusion implosions: axial, mirror, cusp and closed field lines. A mirror field is found to enhance the impact of magnetization over an axial field; this is because the mirror field more closely follows the hot-spot surface. A cusp field, while simple to generate, is not found to have any benefits over the tried-and-tested axial field. Closed field lines are found to be of the greatest benefit to hot-spot performance, with the simulated design undergoing a 2x increase in ion temperature before alpha-heating is considered. The plasma properties of the simulation with closed field lines are radically different from the unmagnetized counterpart, with electron temperatures in excess of 100 keV, suggesting that a fundamental redesign of the capsule implosion is possible if this method is pursued.