A novel method to create an intrinsic reflective layer on a Gd3Ga3Al2O12:Ce scintillation crystal

An innovative method to produce a reflective layer on a scintillation detector element was devised in order to provide an alternative approach to the traditional method of applying extrinsic reflectors. It is known that many inorganic oxides can decompose into suboxides when heated in an oxygen-deficient atmosphere. After heat treating a Gd3Ga3Al2O12 (GGAG) crystal in a reducing atmosphere for several hours we observed that a white surface layer was formed, which was found to have good reflective properties. The resulting reflective layer is robust and firmly attached to the crystal; X-ray diffraction analysis showed that the white reflective layer is primarily composed of GdAlO3. The reflectivity of this reflective layer can reach 92% and the thickness increases with the cumulative soaking time. The performance of the reflective layer in terms of maximizing photon collection was compared to the performance of Teflon tape.