Testing Of A Gamma Ray Imaging System At Omega

Successful images of hard X-rays were taken at the OMEGA Laser at the Laboratory for Laser Energetics at the University of Rochester. This facility served as a surrogate for the National Ignition Facility for which this system was designed. Eleven plastic plastic shells filled with He-3 pellets were imploded producing soft and hard X-rays. As the system was designed to image 4.44 MeV gammas the hard X-rays were of particular interest. These bremsstrahlung X-rays were emitted from the outer plastic shell and imaged using the gamma ray imaging system 13 meters away. A number of filtering arrangements were used to do transmission radiography of the source providing spectrum information. A 200-micron pinhole aperture was used to image the source. These shots provide information critical in characterizing the performance of the system.