Radiation hardening of photographic film in support of x-ray imagers on high neutron yield NIF shots

Time-resolved x-ray imaging is a critical diagnostic tool in inertial confinement fusion (ICF) experiments as it allows for detailed assessment of capsule implosion symmetry, an essential parameter for optimizing implosion performance to achieve higher fusion energy yields. Photographic film has been the primary detection medium for gated x-ray imagers on high yield deuterium-tritium (DT) fusion shots on the National Ignition Facility (NIF) due to its relatively low sensitivity to the adverse effects caused by neutron and gamma radiation, compared to alternatives using electronic readout-based systems such as CCD or CMOS cameras. However, the significant increase in neutron yields since achieving ignition has led to near full saturation of the film. Moreover, partial erasure of the latent image is further degrading the signal-to-noise ratio. These challenges highlight an urgent need to mitigate the deleterious effects of high-radiation environments to preserve data quality and ensure accurate diagnostic interpretation. This work presents ongoing efforts to reduce film sensitivity to neutron and gamma exposure, thereby preserving diagnostic performance in high-yield ICF environments.



Corresponding Author Email: parker76@llnl.gov

This work performed under the auspices of LLNL by General Atomics under subcontract B656918 of Department of Energy Prime Contract No. DE-AC52-07NA27344 and by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

LLNL-ABS-2008706