Improving hot-spot pressure for ignition in high-adiabat Inertial Confinement Fusion implosion

TL;DR

This paper proposes a new capsule design with a high-density pusher to enhance hot-spot pressure in high-adiabat inertial confinement fusion, supported by theoretical scaling laws and simulations, aiming to achieve ignition conditions.

Contribution

It introduces a novel capsule design using a high-density pusher to improve hot-spot pressure based on new stagnation scaling laws, advancing ICF ignition prospects.

Findings

Hot spot pressure reaches ignition threshold in simulations.

Design overcomes ablation and laser-plasma instabilities.

High-adiabat implosion is effective with the new design.

Abstract

A novel capsule target design to improve the hot-spot pressure in the high-adiabat implosion for inertial confinement fusion is proposed, where a layer of comparatively high-density material is used as a pusher between the fuel and the ablator. This design is based on our theoretical finding of the stagnation scaling laws, which indicates that the hot spot pressure can be improved by increasing the kinetic energy density $\rho_d V_{imp}^2/2$ ($\rho_d$ is the shell density when the maximum shell velocity is reached, $V_{imp}$ is the implosion velocity.) of the shell. The proposed design uses the high density pusher to enhance the shell density $\rho_d$ so that the hot spot pressure is improved. Radio-hydrodynamic simulations show that the hot spot pressure of the design reaches the requirement for ignition even driven by a very high-adiabat short-duration two-shock pulse. The design is hopeful to simultaneously overcome the two major obstacles to achieving ignition--ablative instability and laser-plasma instability.