Auxiliary heating of inertial confinement fusion capsules

The ‘auxiliary heating’ technique for ICF implosions is investigated, where relativistic electron beams are used to provide collisionless heating (via the generation and subsequent damping of Langmuir waves) of the central hotspot. Vlasov simulations have previously investigated this process in hotspot-relevant plasmas, and have demonstrated that it can result in a rapid rise in the temperature – with up to 18% of the beam energy being transferred to the plasma electrons. We have investigated the impact of this on fusion performance, by adding electron energy to zones within the hotspot of radiation hydrodynamic simulations of ICF implosions. We present the impact that this has on the yield of a range of different implosions, and estimate the gains that may be achieved using this technique (though these gains are highly dependent on how efficiently such electron beams can be generated). The results suggest that this approach is best suited to implosions which are close to break-even/ignition (rather than implosions which already achieve high gain), with the most optimistic predictions suggesting that it could be used to achieve breakeven for a total laser energy of around 1MJ.