Simulation of Single Mode perturbations on Double Shell Implosions on the National Ignition Facility (NIF)

The LANL double shell platform on the National Ignition facility is a target design that is intended to produce a robust yield by trading relaxed fuel conditions for target complexity [1]. The reliance on kinetic energy transfer from an outer ablator (shell) layer to an inner shell to compress the fuel brings the necessity of investigating shape transfer between shells. This can take a number of different forms including the outer shells imprinting on inner shells as the target implodes, or through the shock’s passage (and reverberation) from one shell to the next. Understanding the amount of transfer, how individual perturbations grow, and the dominant mechanism is an important part in understanding limitations on acceptable initial perturbations.

This presentation will investigate the impact of perturbations with different modes on different interfaces of the double shell point design. This investigation will be done with the HYDRA [2] radiation-hydrodynamics code. We will look at how the mode number influences implosion dynamics, and which interfaces are most susceptible to influence. This will help inform which surfaces must have minimized imprinting, and what the maximum allowable perturbations are.



[1] D.S. Montgomery et al. Phys. Plasmas 25, 092706 (2018)

[2] M.M. Marinak et al. Phys. Plasmas 8, 2275 (2001)



This work conducted under the auspices of the U.S. DOE by LANL under contract 89233218CNA000001, LA-UR-22-26106