@article{oai:repo.qst.go.jp:00046285,
 author = {Yoshida, Eiji and Kinouchi, Shoko and Tashima, Hideaki and Nishikido, Fumihiko and Inadama, Naoko and Murayama, Hideo and Yamaya, Taiga and 吉田 英治 and 木内 尚子 and 田島 英朗 and 錦戸 文彦 and 稲玉 直子 and 村山 秀雄 and 山谷 泰賀},
 issue = {1},
 journal = {Radiological Physics and Technology},
 month = {Nov},
 note = {We have proposed an OpenPET geometry which consists of two axially separated detector rings. The open gap is suitable for in-beam PET. We have developed the small prototype of the OpenPET especially for a proof of concept of in-beam imaging. This paper presents an overview of the main features implemented in this prototype. We also evaluated the detector performance. This prototype was designed with 2 detector rings having 8 depth-of-interaction detectors. Each detector consisted of 784 Lu2xGd2(1-x)SiO5:Ce (LGSO) which were arranged in a 4-layer design, coupled to a position-sensitive photomultiplier tube (PS-PMT). The size of the LGSO array was smaller than the sensitive area of the PS-PMT, so that we could obtain sufficient LGSO identification. Peripheral LGSOs near the open gap directly detect the gamma rays on the side face in the OpenPET geometry. Output signals of two detectors stacked axially were projected onto one 2-dimensional position histogram for reduction of the scale of a coincidence processor. Front-end circuits were separated from the detector head by 1.2-m coaxial cables for the protection of electronic circuits from radiation damage. The detectors had sufficient crystal identification capability. Cross talk between the combined two detectors could be ignored. The timing and energy resolutions were 3.0 ns and 14%, respectively. The coincidence window was set 20 ns, because the timing histogram showed that not only the main peak, but also two small shifted peaks were caused by the coaxial cable. However, the detector offers the promise of sufficient performance, because random coincidences are at a nearly undetectable level for in-beam PET experiments.},
 pages = {92--97},
 title = {System design of a small OpenPET prototype with 4-layer DOI detectors},
 volume = {5},
 year = {2011}
}