Magnetized ICF Implosions: Scaling of Temperature and Yield Enhancement

TL;DR

This study explores how applying magnetic fields to inertial confinement fusion implosions can significantly enhance temperature and yield, especially under certain conditions, with simulations supporting these effects and potential for perturbation suppression.

Contribution

It provides a detailed analysis of temperature and yield scaling in magnetized ICF implosions, highlighting the effects of hot-spot shape, drive asymmetry, and magnetic tension on performance.

Findings

Maximum temperature amplification of 37% predicted for spherical hot-spots.

Yield benefits are greatest for low-temperature, low-perturbation implosions.

Magnetic tension further suppresses perturbations when magnetic fields are strong.

Abstract

This paper investigates the impact of an applied magnetic field on the yield and hot-spot temperature of inertial confinement fusion implosions. A scaling of temperature amplification due to magnetization is shown to be in agreement with unperturbed 2-D extended-magnetohydrodynamic simulations. A perfectly spherical hot-spot with an axial magnetic field is predicted to have a maximum temperature amplification of 37%. However, elongation of the hot-spot along field lines raises this value by decreasing the hot-spot surface area along magnetic field lines. A scaling for yield amplification predicts that a magnetic field has the greatest benefit for low temperature implosions; this is in agreement with simplified 1-D simulations, but not 2-D simulations where the hot-spot pressure can be significantly reduced by heat-flow anisotropy. Simulations including a P2 drive asymmetry then show that the magnetized yield is a maximum when the capsule drive corrects the hot-spot shape to be round at neutron bang-time. The benefit of an applied field increases when the implosion is more highly perturbed. Increasing the magnetic field strength past the value required to magnetize the electrons is beneficial due to additional suppression of perturbations by magnetic tension.