On the change in Inertial Confinement Fusion Implosions upon using an ab initio multiphase DT equation of state

TL;DR

This paper investigates how using an advanced ab initio multiphase DT equation of state affects Inertial Confinement Fusion implosions, optimizing laser pulses and analyzing impacts on target designs for shock and self-ignition.

Contribution

It introduces a new multiphase ab initio EoS for DT and demonstrates its effects on optimizing ICF implosion parameters and target designs.

Findings

Thermonuclear gain remains robust despite EoS uncertainties.

Slight increase in laser energy recovers areal density and energy in shock ignition.

Lower in-flight adiabat is required for self-ignition, delaying shock timing by 3 ns.

Abstract

Improving the description of the equation of state (EoS) of deuterium-tritium (DT) has recently been shown to change significantly the gain of an Inertial Confinement Fusion (ICF) target (Hu et al., PRL 104, 235003 (2010)). We use here an advanced multi-phase equation of state (EoS), based on ab initio calculations, to perform a full optimization of the laser pulse shape with hydrodynamic simulations starting from 19 K in DT ice. The thermonuclear gain is shown to be a robust estimate over possible uncertainties of the EoS. Two different target designs are discussed, for shock ignition and self-ignition. In the first case, the areal density and thermonuclear energy can be recovered by slightly increasing the laser energy. In the second case, a lower in-flight adiabat is needed, leading to a significant delay (3ns) in the shock timing of the implosion.