Fluorescent image converter panel for X-rays comprises layer of columnar crystals with specified diameter ratio defining their individual conicity

摘要

The fluorescence layer includes conically-columnar crystals with diameter ratio D2/D1 between zero and 3. D2 occurs at the surface of the crystals. D1 is 0.1T from the substrate surface. T is the fluorescent layer thickness. An empirical formula with variable coefficients expresses widely ranging compositions of the fluorescent material, which includes an alkali metal, a trivalent metal, a rare earth metal and a halogen. The layer is produced by gas phase deposition, with crystal growth at a given angle, 0-80degrees, with respect to the substrate.