Characterization of foam-filled hohlraums for inertial fusion experiments

TL;DR

This study investigates foam-filled hohlraums in inertial fusion experiments, demonstrating that low-density SiO2 foams effectively reduce wall expansion and maintain low laser backscattering, advancing fusion target design.

Contribution

The paper provides experimental evidence that foam fills can mitigate wall motion and backscattering in hohlraums, a novel approach for improving inertial confinement fusion performance.

Findings

SiO2 foam-fills reduce gold wall expansion

Foam-fills maintain low laser backscattering

Low-density foams are effective in hohlraum stabilization

Abstract

On the path towards high-gain inertial confinement fusion ignition, foams are being considered to tamp the hohlraum wall-motion, and mitigate laser backscattering from Stimulated Raman Scattering (SRS) and Stimulated Brillouin Scattering (SBS). Here we present the results from an experimental campaign on foam-filled hohlraums conducted at the OMEGA laser facility. SiO2 foam-fills, with densities as low as 1 mg/cm3, successfully reduce the gold wall expansion, with laser backscattering comparable to gas-fill.