Neutron imaging development for inertial confinement fusion experiments

Various failure mechanisms may limit fuel compression and ignition during Inertial Confinement Fusion (ICF) experiments with MegaJoule class lasers (e.g., the Laser M\'{e}gaJoule: LMJ and the National Ignition Facility: NIF). A Neutron Imaging System (NIS) may be used to determine the asymmetries in the hot core and the surrounding cold fuel shell. To reveal such asymmetries, a NIS must record both a primary (14 MeV) and a down-scattered (5-10 MeV) neutron image with high SNR and an image plane spatial resolution as low as 5 $\mu $m. We report on the continuing development of an NIS diagnostic at the OMEGA laser facility, using coded apertures. A new large neutron camera (150 mm entrance diameter: scaled for LMJ/NIF design) has been activated at OMEGA. This camera will allow 5 $\mu $m resolution for LMJ neutron source. We have tested a set of three detectors that can be used for various NIS diagnostic experiments on OMEGA from low yield (10$^{9}$-10$^{10}$ neutrons) low resolution (32 $\mu $m) measurements at 4 m from the neutron source to high yield (10$^{12}$-10$^{14}$ neutrons) high resolution (15 $\mu $m) measurements at 13 m. The low yield configuration allowed us to record, the first neutron image on an indirect drive shot with pure deuterium filled capsules.