Using neutron and X-ray images of layered HDC implosion on the NIF to reconstruct hotspot conditions during burn*

The time-integrated neutron image(s) of a layered implosion on the NIF, under an isobaric assumption, allows the reconstruction of the density and temperature profile of the central hotspot. The measured neutron yield and spectral width constrain the stagnation pressure. One can then look for signatures of various degradation mechanisms. For instance, one can compare a co-registered X-ray image to a synthetic reconstruction and assess the impact of Carbon penetrating the hot spot through mix and the fill-tube jet. The method will be validated using simulated images and applied to a series of recent high-performing HDC implosions [1]. 

[1] “Fusion energy output greater than the kinetic energy of an imploding shell at the National Ignition Facility”, S. LePape et al., Phys. Rev. Lett. 120, 245003 (2018)