Design and modeling of a unity-gain platform at 1.9 MJ of laser drive on the National Ignition Facility through optimized shock timing

The Hybrid-E Shock Merge campaign is assessing the impact of increased compression on performance relative to the N210808 high-yield experiment. Simulations suggest that modifications to the shock timing of N210808 could increase the performance via reduced adiabat; this is achieved by merging the first and second shocks closer to the ice/gas interface, and lengthening the time during which the laser rises to peak power to reduce the entropy generated by the reflected shock. 

 

In this talk we will discuss the design of the Shock Merge experiments and the expected improvements relative to N210808. We will discuss the challenges and lessons learned from the initial experiments, and how that information led to subtle design changes for the NIF experiment N230605, the first experiment to achieve target gain of unity within the experimental uncertainties at 1.9MJ of laser drive energy. Finally, we will consider how similar shock timing modifications could impact performance in the 2.05MJ Hybrid-E platform. 

 

Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-851373.