The Shock-Augmented Ignition Approach to Laser Inertial Fusion

Shock-Augmented Ignition¹ (SAI) is a new Laser Inertial Fusion concept which seeks to tread an optimal middle ground between Central Hotspot Ignition² and Shock Ignition³. By employing a dip in laser-power followed by a rapid rise, simulations indicate that for direct drive implosions, SAI enables the generation of a strong shock without the high laser intensity conventionally thought to be required for shock ignition. This in turn enables higher fusion energy-gain at a lower implosion velocity. 

Our work shows that SAI should also be beneficial for indirect drive, although due to the limited rise rate in the radiation temperature, the physics is somewhat different. According to simulations the power dip results in higher yield with more stable implosions which also increase the yield over clean. In addition, the power dip reduces the impact of the ‘n+1’ shock.

In this talk I will discuss the Shock-Augmented Ignition concept, results from simulations, and experiments performed on both the National Ignition Facility, Lawrence Livermore National Laboratory and the Omega laser facility at the Laboratory for Laser Energetics. 

 

¹ Scott et al, Physical Review Letters, (2022).

² Nuckolls et al, Nature, (1972).

³ Betti et al, Physical Review Letters (2007).