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Maeda, Shigetaka; Nogami, Mitsuhiro*; Ito, Chikara; Watanabe, Kenichi*; Hitomi, Keitaro*
no journal, ,
A portable high-resolution gamma-ray spectrometer for nuclear facilities is developing. The research plan will be outlined, and the applicability to OLGM for fast reactor fuel failure detection and the required performance will be reported.
Nogami, Mitsuhiro*; Hitomi, Keitaro*; Ito, Chikara; Tsubakiyama, Kunimi*; Watanabe, Kenichi*; Maeda, Shigetaka
no journal, ,
While many studies have been conducted on improving energy resolution and increasing the volume of TlBr detectors, little evaluation has been made on long-term stability. Therefore, in this study, we evaluated the long-term stability of the TlBr detector when it was operated continuously for about 2000 hours, assuming application to an actual nuclear power plant.
Watanabe, Kenichi*; Tsubakiyama, Kunimi*; Hitomi, Keitaro*; Nogami, Mitsuhiro*; Ito, Chikara; Maeda, Shigetaka
no journal, ,
The crystallinity of TlBr crystals was evaluated using the neutron Bragg dip imaging method, which is one of the neutral diffraction methods, as a part of the study for improving the detector performance.
Watanabe, Kenichi*; Hitomi, Keitaro*; Nogami, Mitsuhiro*; Maeda, Shigetaka; Ito, Chikara; Tanno, Takashi; Onabe, Hideaki*
no journal, ,
TlBr is a compound semiconductor with a high atomic number, high density and a wide bandgap, and is being developed as a gamma-ray detector material that can be operated at room temperature and has high detection efficiency. There is neutron diffraction in order to establish a crystal quality evaluation method for improving the yield in device fabrication, but the facilities that can be implemented are limited to large facilities such as J-PARC. The Electron Backscatter Diffraction (EBSD) image, which is one of the electron beam diffractions, can be obtained with an electron microscope, but only the information on the crystal surface can be obtained. In this study, the crystal orientation image was acquired for the TlBr crystal by neutron Bragg dip imaging, which is one of the neutron diffractions, and EBSD. By comparing both images, the applicability to a simple EBSD crystal quality evaluation method was examined.
Watanabe, Kenichi*; Hitomi, Keitaro*; Nogami, Mitsuhiro*; Maeda, Shigetaka; Onabe, Hideaki*
no journal, ,
TlBr is a compound semiconductor with a high atomic number and density, and a wide bandgap. TlBr detector is being developed as a gamma-ray detector material that can operate at room temperature and has high detection efficiency. The current issue is to improve the yield in device manufacturing, and it is required to establish a process that can stably manufacture high quality devices. The crystal growth process is one of the most important processes in producing a good quality detector, and it is very important to understand how crystals are grown. This time, we tried to obtain knowledge about crystal growth by observing the crystal orientation distribution in the crystal growth direction.
Nogami, Mitsuhiro*; Kitayama, Yoshiharu; Hitomi, Keitaro*
no journal, ,
no abstracts in English
Watanabe, Kenichi*; Hitomi, Keitaro*; Nogami, Mitsuhiro*; Maeda, Shigetaka; Onabe, Hideaki*
no journal, ,
Thallium bromide (TlBr) is a compound semiconductor attractive for gamma-ray spectrometers. TlBr detectors have shown excellent energy resolution, however, these results were obtained from relatively small crystal detectors. The next phase of TlBr development is to increase the detector size and improve the yield rate of detector production. So far, we have evaluated crystal quality of TlBr by using the neutron Bragg-dip imaging, which is one of the neutron diffraction techniques. In this study, we prepared a large TlBr crystal wafer with a diameter and thickness of 50 mm and 12 mm, respectively. We evaluated the quality of the large crystal by the neutron Bragg-dip imaging. The center region of the large TlBr crystal confirmed to be uniform and well-aligned. As a future work, we will evaluate the electric properties, such as the mobility-lifetime product, at various positions in this large crystal.