Development of a high-efficiency high-resolution imaging detector for 30–80 keV X-rays

A newly developed fabrication method makes the formation of deep structured scintillator screens possible. We demonstrate that electrochemical etching in silicon can be used to produce regular arrays of 120 μm deep pores with a 4 μm pitch. A layer of SiO2 is grown on the pore walls and CsI:Tl is melted into the pores, resulting in a structure with a high refractive index core surrounded by a quartz cladding, providing efficient light guiding. The efficiency and radiation hardness of the scintillator is evaluated in realistic environment at beamline ID15 at the ESRF synchrotron. The efficiency is measured to be a factor two higher than a planar YAG: Ce scintillator of equal thickness, while radiation damage is found to be neglectable for doses up to at least 2×104 Gy.