A Hybrid Scheme to Achieve Highest Implosion Performance on the OMEGA Laser

TL;DR

This paper introduces a novel hybrid laser-fusion scheme combining direct and indirect drive methods, demonstrated through 2D simulations to enhance implosion performance and fusion yields on the OMEGA laser.

Contribution

First integrated 2D simulations of hybrid shock drive targets showing improved implosion stability and higher fusion yields for the OMEGA laser system.

Findings

HSD scheme suppresses hydrodynamic instabilities

Projected 85% increase in Lawson parameter on OMEGA

Eliminates need for laser smoothing techniques

Abstract

Merging direct and indirect-drive has long been viewed as an optimal hybrid laser-fusion scheme that combines the uniformity of x rays with the efficiency of direct illumination. We present the first integrated 2D simulations of hybrid shock drive (HSD) targets for the OMEGA laser. The HSD scheme [L. Ceurvorst et al., Phys. Rev. E 101 063207 (2020)] uses x rays from a thin Au-coated x-ray converter outer shell to drive the initial shock into a standard direct-drive capsule. Direct illumination is used to implode the target after the first shock. The design effectively suppresses laser-imprint seeding of hydrodynamic instabilities, maintaining shell integrity during the implosion. This scheme will enable fielding low-adiabat, high-convergence implosions on OMEGA with expected performance greatly exceeding those of current designs. HSD targets are projected to significantly enhance fusion yields, potentially increasing the record Lawson parameter by $\sim$85\% on OMEGA while effectively eliminating the requirement for laser smoothing. These results position HSD as a robust platform for high-performance implosions, paving the way for advanced high-gain inertial fusion energy targets.