Proposal of a 8-layer DOI detector composed of same scintillation crystal elements

Previously, we developed a 4-layer depth of interaction (DOI) detector. It is composed of four layers of a scintillation crystal array and a position sensitive photomultiplier tube (PS-PMT) and by removing some reflectors between the crystal elements in the array, we control scintillation light distribution on the PS-PMT so that the responses of all crystal elements are discriminated. We also proposed a 2-layer DOI encoding method that uses the crystal elements cut as a triangular prism and proved its capability. Combining these two methods, here we propose an 8-layer DOI encoding method. The method makes it possible that the 8-layer DOI detector is consisted of same scintUlation crystal elements, that is to say, any scintillation crystals. The method was demonstrated with the Lu_2xG_d2(LGSO, x = 0.9) crystals. The obtained results indicated the possibility of the proposed method.