Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Yomogida, Takumi; Hashimoto, Tadashi; Okumura, Takuma*; Yamada, Shinya*; Tatsuno, Hideyuki*; Noda, Hirofumi*; Hayakawa, Ryota*; Okada, Shinji*; Takatori, Sayuri*; Isobe, Tadaaki*; et al.
Analyst, 149(10), p.2932 - 2941, 2024/03
In this study, we successfully applied a transition-edge sensor (TES) spectrometer as a detector for microbeam X-ray measurements from a synchrotron X-ray light source to determine uranium (U) distribution at the micro-scale and its chemical species in biotite obtained from the U mine. It is difficult to separate the fluorescent X-ray of the U L line at 13.615 keV from that of the Rb K line at 13.395 keV in the X-ray fluorescence spectrum with an energy resolution of approximately 220 eV of the conventional silicon drift detector (SDD). Meanwhile, the fluorescent X-rays of U L and Rb K were fully separated by TES with 50 eV energy resolution at the energy of around 13 keV. The successful peak separation by TES led to an accurate mapping analysis of trace U in micro-X-ray fluorescence measurements and a decrease in the signal-to-background ratio in micro-X-ray absorption near edge structure spectroscopy.
Fujita, Natsuko; Miyake, Masayasu; Matsubara, Akihiro*; Ishii, Masahiro*; Watanabe, Takahiro; Jinno, Satoshi; Nishio, Tomohiro*; Ogawa, Yumi; Kimura, Kenji; Shimada, Akiomi; et al.
Dai-35-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.17 - 19, 2024/03
The JAEA-AMS-TONO facility at the Tono Geoscience Center, JAEA has three accelerator mass spectrometers. We report the present status of the JAEA-AMS-TONO.
Li, W.*; Yamada, Shinya*; Hashimoto, Tadashi; Okumura, Takuma*; Hayakawa, Ryota*; Nitta, Kiyofumi*; Sekizawa, Oki*; Suga, Hiroki*; Uruga, Tomoya*; Ichinohe, Yuto*; et al.
Analytica Chimica Acta, 1240, p.340755_1 - 340755_9, 2023/02
Times Cited Count:4 Percentile:52.44(Chemistry, Analytical)no abstracts in English
Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I.-H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.
IEEE Transactions on Applied Superconductivity, 31(5), p.2101704_1 - 2101704_4, 2021/08
Times Cited Count:1 Percentile:10.16(Engineering, Electrical & Electronic)A superconducting transition-edge sensor (TES) microcalorimeter is an ideal X-ray detector for experiments at accelerator facilities because of good energy resolution and high efficiency. To study the performance of the TES detector with a high-intensity pulsed charged-particle beam, we measured X-ray spectra with a pulsed muon beam at the Japan Proton Accelerator Research Complex (J-PARC) in Japan. We found substantial temporal shifts of the X-ray energy correlated with the arrival time of the pulsed muon beam, which was reasonably explained by pulse pileup due to the incidence of energetic particles from the initial pulsed beam.
Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I. H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.
Physical Review Letters, 127(5), p.053001_1 - 053001_7, 2021/07
Times Cited Count:15 Percentile:82.53(Physics, Multidisciplinary)We observed electronic X rays emitted from muonic iron atoms using a superconducting transition-edge-type sensor microcalorimeter. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic and X rays together with the hypersatellite X rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the -shell electrons, accompanied by electron side-feeding. Assisted by a simulation, this data clearly reveals the electronic - and -shell hole production and their temporal evolution during the muon cascade process.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count:44 Percentile:96.99(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Yamaguchi, Mitsutaka; Torikai, Kota*; Kawachi, Naoki; Shimada, Hirofumi*; Sato, Takahiro; Nagao, Yuto; Fujimaki, Shu; Kokubun, Motohide*; Watanabe, Shin*; Takahashi, Tadayuki*; et al.
Physics in Medicine & Biology, 61(9), p.3638 - 3644, 2016/05
Times Cited Count:9 Percentile:100(Engineering, Biomedical)no abstracts in English
Yamaguchi, Mitsutaka; Nagao, Yuto; Kawachi, Naoki; Fujimaki, Shu; Kamiya, Tomihiro; Odaka, Hirokazu*; Kokubun, Motohide*; Takeda, Shinichiro*; Watanabe, Shin*; Takahashi, Tadayuki*; et al.
Proceedings of 2013 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC), 3 Pages, 2013/00
Yamaguchi, Mitsutaka; Torikai, Kota*; Kawachi, Naoki; Shimada, Hirofumi*; Sato, Takahiro; Nagao, Yuto; Fujimaki, Shu; Kokubun, Motohide*; Watanabe, Shin*; Takahashi, Tadayuki*; et al.
Proceedings of 2013 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC), 2 Pages, 2013/00
Odaka, Hirokazu*; Ichinohe, Yuto*; Takeda, Shinichiro*; Fukuyama, Taro*; Hagino, Koichi*; Saito, Shinya*; Sato, Tamotsu*; Sato, Goro*; Watanabe, Shin*; Kokubun, Motohide*; et al.
Nuclear Instruments and Methods in Physics Research A, 695, p.179 - 183, 2012/12
Times Cited Count:23 Percentile:83.76(Instruments & Instrumentation)We have developed a new Si/CdTe semiconductor double-sided strip detector (DSD) Compton camera. The camera consists of a 500-m-thick Si-DSD and four layers of 750-m-thick CdTe-DSDs all of which have common electrode configuration segmented into 128 strips on each side with pitches of 250m. In order to realize high angular resolution and to reduce size of the detector system, a stack of DSDs with short stack pitches of 4 mm is utilized to make the camera. Taking advantage of the excellent energy and position resolutions of the semiconductor devices, the camera achieves high angular resolutions of 4.5 degrees at 356 keV and 3.5 degrees at 662 keV. To obtain such high resolutions together with an acceptable detection efficiency, we demonstrate data reduction methods including energy calibration using Compton scattering continuum and depth sensing in the CdTe-DSD. We also discuss imaging capability of the camera and show simultaneous multi-energy imaging.
Takeda, Shinichiro*; Ichinohe, Yuto*; Hagino, Koichi*; Odaka, Hirokazu*; Yuasa, Takayuki*; Ishikawa, Shinnosuke*; Fukuyama, Taro*; Saito, Shinya*; Sato, Tamotsu*; Sato, Goro*; et al.
Physics Procedia, 37, p.859 - 866, 2012/10
Times Cited Count:23 Percentile:98.48(Physics, Applied)By using new Compton camera consisting of silicon double-sided strip detector (Si-DSD) and CdTe-DSD developed for the ASTRO-H mission, an experiment was conducted to study its feasibility for advanced hotspot monitoring. In addition to hotspot imaging already provided by commercial imaging systems, the identification of the variety of radioisotopes is realized thanks to the good energy resolution given by the semiconductor detectors. Three radioisotopes of Ba (356 keV), Na (511 keV) and Cs (662 keV) were individually imaged by applying event selection in the energy window and the -ray images was correctly overlapped by an optical picture. The detection efficiency of 1.6810 (effective area: 1.710 cm) and angular resolution of 3.8 were obtained by stacking five detector modules for 662 keV -ray. The higher detection efficiency required in a specific use can be achieved by stacking more detector modules.
Yamaguchi, Mitsutaka; Torikai, Kota*; Kawachi, Naoki; Shimada, Hirofumi*; Sato, Takahiro; Nagao, Yuto; Fujimaki, Shu; Kokubun, Motohide*; Watanabe, Shin*; Takahashi, Tadayuki*; et al.
Physics in Medicine & Biology, 57(10), p.2843 - 2856, 2012/05
Times Cited Count:41 Percentile:79.69(Engineering, Biomedical)Kawachi, Naoki; Yamaguchi, Mitsutaka; Nagao, Yuto; Suzui, Nobuo; Fujimaki, Shu; Kamiya, Tomihiro; Odaka, Hirokazu*; Kokubun, Motohide*; Takeda, Shinichiro*; Ishikawa, Shinnosuke*; et al.
no journal, ,
Kawachi, Naoki; Suzui, Nobuo; Ishii, Satomi; Yamazaki, Haruaki; Yin, Y.-G.; Yamaguchi, Mitsutaka; Nagao, Yuto; Kamiya, Tomihiro; Takahashi, Tadayuki*; Nakano, Takashi*; et al.
no journal, ,
no abstracts in English
Nagao, Yuto; Yamaguchi, Mitsutaka; Kawachi, Naoki; Fujimaki, Shu; Kamiya, Tomihiro; Takeda, Shinichiro*; Odaka, Hirokazu*; Watanabe, Shin*; Kokubun, Motohide*; Takahashi, Tadayuki*; et al.
no journal, ,
A conventional -ray imaging system such as a gamma camera and SPECT has a fundamental problem that imposes a tradeoff between sensitivity and spatial resolution and restricts -ray energy to low because of the physical constraints resulting from the mechanical collimation. On the other hand, a Compton camera, which applies kinematics of Compton scattering to the electronic collimation, is a next generation -ray imaging system which decouples the tradeoff between sensitivity and spatial resolution and covers a wide range of energy. We study an application of a Si/CdTe semiconductor Compton camera being developed for space observation to in vivo tracer imaging in medicine and biology. Particularly, it is essential for a medical and biological application to estimate quantitative distribution of tracers in a field close to the camera. We developed an image reconstruction method to realize quantitative profiling of -ray emitting sources.
Nagao, Yuto; Yamaguchi, Mitsutaka; Kawachi, Naoki; Fujimaki, Shu; Kamiya, Tomihiro; Takeda, Shinichiro*; Watanabe, Shin*; Takahashi, Tadayuki*; Torikai, Kota*; Arakawa, Kazuo*; et al.
no journal, ,
no abstracts in English
Yamaguchi, Mitsutaka; Nagao, Yuto; Kawachi, Naoki; Fujimaki, Shu; Arakawa, Kazuo*; Kamiya, Tomihiro; Odaka, Hirokazu*; Kokubun, Motohide*; Takeda, Shinichiro*; Watanabe, Shin*; et al.
no journal, ,
no abstracts in English
Nagao, Yuto; Yamaguchi, Mitsutaka; Kawachi, Naoki; Fujimaki, Shu; Kamiya, Tomihiro; Takeda, Shinichiro*; Watanabe, Shin*; Takahashi, Tadayuki*; Torikai, Kota*; Arakawa, Kazuo*; et al.
no journal, ,
Kawachi, Naoki; Suzui, Nobuo; Ishii, Satomi; Yin, Y.-G.; Yamaguchi, Mitsutaka; Nagao, Yuto; Kamiya, Tomihiro; Takahashi, Tadayuki*; Nakano, Takashi*; Fujimaki, Shu
no journal, ,
no abstracts in English
Yamaguchi, Mitsutaka; Sakai, Makoto*; Nagao, Yuto; Kawachi, Naoki; Fujimaki, Shu; Arakawa, Kazuo*; Kamiya, Tomihiro; Odaka, Hirokazu*; Kokubun, Motohide*; Takeda, Shinichiro*; et al.
no journal, ,
no abstracts in English