Optimization of gated x-ray intensifier screens

Gated x-ray intensifiers are primary imaging diagnostics in high energy density physics and inertial confinement fusion experiments. We describe recent work in optimization of the phosphor screens used in these intensifiers. One avenue for improvement in resolution, contrast, and brightness is improved phosphor screens. Efforts have been directed at improving luminosity, resolution, and contrast with an aluminized thin (<0.7 μg/cm2) phosphor layer, a higher transmission indium tin oxide (ITO) electrode, and higher density screens. Thinner phosphors, coupled with thinner aluminum overcoats (<500 A ring ), should give equivalent or higher luminosities than traditional thick (<0.7μg/cm2) settled coatings in the electron energy range between 3 and 5 kV, typical microchannel plate to screen accelerating voltages for this class of instrument. Higher resolution is achieved by coupling increased extraction voltage (ph/e-) with less interparticle photon diffusion and increased photon capture (aluminum overcoat). The contribution of the aluminum overcoat to capturing backscattered screen photons is examined. Improved transmission of an ITO electrode used in the cataphoretic deposition technique is demonstrated