Physica B 385–386 (2006) 1297–1299 Development of neutron Anger-camera detector based on flatpanel PMT Katsuya Hirota a,Ã , Setsuo Satoh b , Kenji Sakai c , Takenao Shinohara a , Kazuaki Ikeda a , Kenji Mishima a , Satoru Yamada c , Takayuki Oku c , Jun-ichi Suzuki c , Michihiro Furusaka b,d , Hirohiko M. Shimizu a,Ã a Riken, 2-1 Wako, Saitama 351-0198, Japan b KEK, Oho, Tsukuba, Ibaraki 305-0801, Japan c Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan d Hokkaido Univ, Sapporo 060-8628, Japan Abstract A neutron scintillating detector and its data taking system have been developed for neutron scattering measurement. A 64-channel flatpanel photomultiplier is used for the Anger-camera method. The detection efficiency of g-ray background is very low in the use of the ZnS/ 6 LiF scintillator. The spatial resolution is less than 1 mm. The effective area of this detector is around 25 cm 2 , and it is easy to expand it to a larger area with small dead space using the multi-photomultiplier tubes system. The fast DAQ system has 10-bit 100 MHz flash ADCs, FPGA chips and USB2.0 device. r 2006 Elsevier B.V. All rights reserved. PACS: 07.05.Hd; 42.79.Pw; 61.12 Keywords: Neutron detector; Scintillator; Imaging 1. Introduction Neutron scattering is a powerful tool in areas of soft materials and biological science. Recently, neutron optical devices such as neutron magnetic lens and material lens for cold neutron beam have been developed [1]. These devices require good spatial resolution of less than 1 mm 2 and a high count rate DAQ system for the neutron detector. Traditional position-sensitive detectors using 3 He gas, which are widely applied in neutron experiments, have high neutron-detection efficiency and high S/N ratio but their spatial resolution, typically 5 mm, is not suitable with such focusing devices. We have, therefore, developed a scintillation neutron imaging detector [2–4]. The cross-fiber detector [2] has a good spatial resolution of 0.5 mm but low detection efficiency and low S/N ratio because of the use of wavelength-shifting fibers. The RPMT detector [3] also has good spatial resolution of less than 1 mm and user- friendly data taking system, but has a large dead space in the peripheral area of the detector and it is hard to expand the effective area. The neutron imaging detector applying the Anger-camera method [5,6] has several advantages, good spatial resolution smaller than its pixel size, high detection efficiency and small or less dead space for constructing a larger area detector. This paper outlines the developed ‘flatpanel Anger detector’. 2. Anger-camera method The schematic structure of this detector is explained in Ref. [4]. A 64-channel flatpanel photomultiplier tube (FPMT), Hamamatsu H8500 is used. The scintillator is 0.25 mm-thick ZnS/ 6 LiF which has a large light yield, more than 10,000 photons, for cold and thermal neutrons. The ARTICLE IN PRESS www.elsevier.com/locate/physb 0921-4526/$ - see front matter r 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.physb.2006.06.058 Ã Corresponding author. Tel.: +81 48 467 9723; fax: +81 48 467 9721. E-mail address: katsuya-hirota@riken.jp (K. Hirota).