Role of self-generated magnetic fields in the inertial fusion ignition threshold

Magnetic fields spontaneously grow at unstable interfaces around hot-spot asymmetries during inertial confinement fusion implosions. Although difficult to measure, theoretical considerations and numerical simulations predict field strengths exceeding 5 kT in current National Ignition Facility experi...

Full description

Saved in:
Bibliographic Details
Published in:Physics of plasmas 2022-07, Vol.29 (7)
Main Authors: Sadler, James David, Walsh, Christopher A., Zhou, Ye, Li, Hui
Format: Article
Language:English
Subjects:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
alpha particles
computer simulation
energy balance model
fluid instabilities
fusion energy
hydrodynamics simulations
magnetic fields
nuclear energy
nuclear fusion
plasma confinement
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Magnetic fields spontaneously grow at unstable interfaces around hot-spot asymmetries during inertial confinement fusion implosions. Although difficult to measure, theoretical considerations and numerical simulations predict field strengths exceeding 5 kT in current National Ignition Facility experiments. Magnetic confinement of electrons then reduces the rate of hot-spot heat loss by >5%. We demonstrate this via magnetic post-processing of two-dimensional xRAGE hydrodynamic simulation data at bang time. We then derive a model for the self-magnetization, finding that it varies with the square of the hot-spot temperature and inversely with the areal density. The self-magnetized Lawson analysis then gives a slightly reduced ignition threshold. Time-dependent hot-spot energy balance models corroborate this finding, with the magnetic field quadrupling the fusion yield for near-threshold parameters. The inclusion of magnetized multi-dimensional fluid instabilities could further alter the ignition threshold and will be the subject of future work.
ISSN:1070-664X