부산대학교 도서관

Summary form only given, as follows. We have installed the National Ignition Facility Neutron Imaging System. The imaging system provides information about the areal density of fuel in the various regions of the capsule implosion. A long line of sight enables imaging both the primary 14 MeV neutrons as well as the down-scattered neutrons with energies in the range of 9–12 MeV. The imager is a pinhole camera where the pinhole is located 325 mm from the target and the imaging plane is located 28 m from the target. The long absorption length of neutrons requires precise alignment of these extended imager components in order to have high detection efficiency and strong background rejection.