@article{oai:repo.qst.go.jp:00046722,
 author = {Ogata, Yuma and Ohnishi, Takashi and Moriya, Takahiro and Inadama, Naoko and Nishikido, Fumihiko and Yoshida, Eiji and Murayama, Hideo and Yamaya, Taiga and Haneishi, Hideaki and 大西 峻 and 森谷 隆広 and 稲玉 直子 and 錦戸 文彦 and 吉田 英治 and 村山 秀雄 and 山谷 泰賀 and 羽石 秀昭},
 issue = {1},
 journal = {Radiological physics and technology},
 month = {Jan},
 note = {The X'tal cube is a next-generation DOI detector for PET that we are developing to offer higher resolution and higher sensitivity than is available with present detectors. It is constructed from a cubic monolithic scintillation crystal and silicon photomultipliers which are coupled on various positions of the six surfaces of the cube. A laser-processing technique is applied to produce 3D optical boundaries composed of micro-cracks inside the monolithic scintillator crystal. The current configuration is based on an empirical trial of a laser-processed boundary. There is room to improve the spatial resolution by optimizing the setting of the laser-processed boundary. In fact, the laser-processing technique has high freedom in setting the parameters of the boundary such as size, pitch, and angle. Computer simulation can effectively optimize such parameters. In this study, to design optical characteristics properly for the laser-processed crystal, we developed a Monte Carlo simulator which can model arbitrary arrangements of laser-processed optical boundaries (LPBs). The optical characteristics of the LPBs were measured by use of a setup with a laser and a photo-diode, and then modeled in the simulator. The accuracy of the simulator was confirmed by comparison of position histograms obtained from the simulation and from experiments with a prototype detector composed of a cubic LYSO monolithic crystal with 6 × 6 × 6 segments and multi-pixel photon counters. Furthermore, the simulator was accelerated by parallel computing with general-purpose computing on a graphics processing unit. The calculation speed was about 400 times faster than that with a CPU.},
 title = {GPU-based optical propagation simulator of a laser-processed crystal block for the X'tal cube PET detector.},
 volume = {7},
 year = {2014}
}