Volume Ignition via Time-like Detonation in Pellet Fusion

TL;DR

This paper models relativistic fluid dynamics and detonation theory to propose a method for rapid, volume ignition in pellet fusion, aiming for near-simultaneous target ignition to prevent instabilities.

Contribution

It introduces a relativistic, radiation-dominated model for volume ignition in pellet fusion, emphasizing the importance of ultra-fast heating pulses for stable, simultaneous ignition.

Findings

Rapid ignition pulse (<10 ps) can heat the entire target to supercritical temperatures.

Relativistic, radiation-dominated processes stabilize the ignition front.

Volume ignition prevents development of Rayleigh-Taylor instabilities.

Abstract

Relativistic fluid dynamics and the theory of relativistic detonation fronts are used to estimate the space-time dynamics of the burning of the D-T fuel in Laser driven pellet fusion experiments. The initial "High foot" heating of the fuel makes the compressed target transparent to radiation, and then a rapid ignition pulse can penetrate and heat up the whole target to supercritical temperatures in a short time, so that most of the interior of the target ignites almost simultaneously and instabilities will have no time to develop. In these relativistic, radiation dominated processes both the interior, time-like burning front and the surrounding space-like part of the front will be stable against Rayleigh-Taylor instabilities. To achieve this rapid, volume ignition the pulse heating up the target to supercritical temperature should provide the required energy in less than ~ 10 ps.