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Takyu, Sodai*; Matsumoto, Kenichiro*; Hirade, Tetsuya; Nishikido, Fumihiko*; Akamatsu, Go*; Tashima, Hideaki*; Takahashi, Miwako*; Yamaya, Taiga*
Japanese Journal of Applied Physics, 63(8), p.086003_1 - 086003_8, 2024/08
Positrons and electrons sometimes exist as a bound state, positronium (Ps), in living organisms. The triplet Ps (ortho-Ps) annihilation time represents the ortho-Ps pick-off annihilation lifetime, and it varies depending on the surrounding electron density. The ortho-Ps lifetime may add new biological information to PET scan information. In order to discuss the feasibility of quantifying (free) radicals in vivo by the ortho-Ps lifetime, we used a clinical PET system to make ortho-Ps lifetime measurements in aqueous solutions containing radicals. The results suggested that differences in radical concentrations in aqueous solutions of the order of a few mM could be quantified by the ortho-Ps lifetime if the counting statistic of the positron annihilation events was more than 10 events. This concentration was higher than the radical concentration generated in the physiological functions of living organisms.
Kawasaki, Takuro; Takahashi, Miwako*; Kiyanagi, Ryoji; Ohara, Takashi
Acta Crystallographica Section C; Structural Chemistry (Internet), 78(12), p.743 - 748, 2022/12
Times Cited Count:0 Percentile:0.00(Chemistry, Multidisciplinary)Ohara, Takashi; Kiyanagi, Ryoji; Oikawa, Kenichi; Kaneko, Koji; Kawasaki, Takuro; Tamura, Itaru; Nakao, Akiko*; Hanashima, Takayasu*; Munakata, Koji*; Moyoshi, Taketo*; et al.
Journal of Applied Crystallography, 49(1), p.120 - 127, 2016/02
Times Cited Count:55 Percentile:95.88(Chemistry, Multidisciplinary)Oikawa, Kenichi; Kawasaki, Takuro; Ohara, Takashi; Kiyanagi, Ryoji; Kaneko, Koji; Tamura, Itaru; Nakamura, Tatsuya; Harada, Masahide; Nakao, Akiko*; Hanashima, Takayasu*; et al.
JPS Conference Proceedings (Internet), 1, p.014013_1 - 014013_5, 2014/03
A new single crystal time-of-flight neutron diffractometer has been installed at BL18 of the Materials and Life Science Experimental Facility of J-PARC. The diffractometer "SENJU" was designed for precise crystal and magnetic structure analyses using a small crystal less than 1.0 mm under multiple extreme environments such as low-temperature and high-magnetic field. The first neutron beam was delivered to the sample position on March 5, 2012. Subsequently, the hardware and software of SENJU have been checked and confirmed that they worked fine. At the same time, diffraction experiments of several organic and inorganic crystals have been done using NaCl, C12A7, and so on. In these measurements, Bragg reflections in the high-Q region (d-spacing
0.5
) were clearly observed and analyzed successfully. In this presentation, we will show the instrument design and performance evaluation of SENJU in detail.
Kawasaki, Takuro; Takahashi, Miwako*; Ohara, Takashi*; Tanaka, Ichiro*; Kusaka, Katsuhiro*; Hosoya, Takaaki*; Yamada, Taro*; Kurihara, Kazuo
Journal of the Physical Society of Japan, 81(9), p.094602_1 - 094602_6, 2012/09
Times Cited Count:7 Percentile:45.79(Physics, Multidisciplinary)Tamura, Itaru; Oikawa, Kenichi; Kawasaki, Takuro; Ohara, Takashi; Kaneko, Koji; Kiyanagi, Ryoji; Kimura, Hiroyuki*; Takahashi, Miwako; Kiyotani, Tamiko*; Arai, Masatoshi; et al.
Journal of Physics; Conference Series, 340, p.012040_1 - 012040_4, 2012/02
Times Cited Count:11 Percentile:94.26(Physics, Condensed Matter)Kiyanagi, Ryoji; Ohara, Takashi*; Kawasaki, Takuro; Oikawa, Kenichi; Tamura, Itaru; Kaneko, Koji; Hanashima, Takayasu*; Nakao, Akiko*; Munakata, Koji*; Kimura, Hiroyuki*; et al.
no journal, ,
no abstracts in English
Ohara, Takashi; Kiyanagi, Ryoji; Kawasaki, Takuro; Oikawa, Kenichi; Kaneko, Koji; Tamura, Itaru; Nakao, Akiko*; Hanashima, Takayasu*; Munakata, Koji*; Kimura, Hiroyuki*; et al.
no journal, ,
SENJU is a new single crystal time-of-flight neutron diffractometer installed at BL18 of J-PARC. SENJU is designed for precise crystal and magnetic structure analyses under multiple extreme environments such as low-temperature, high-pressure and high-magnetic field, and also designed for diffraction measurements of small single crystals less than 1.0 mm in volume. We have successfully achieved structure analysis of a laboratory X-ray size (0.1 mm
) single organic crystal, measurement and visualization of a complex-shape diffuse scattering pattern and measurement of higher order magnetic reflections in high-Q region (Q
16
) by using SENJU. Those results show that the performance of SENJU is as we expected.
Kiyanagi, Ryoji; Ohara, Takashi; Kawasaki, Takuro; Oikawa, Kenichi; Kaneko, Koji; Tamura, Itaru; Nakao, Akiko*; Hanashima, Takayasu*; Munakata, Koji*; Moyoshi, Taketo*; et al.
no journal, ,
The single crystal diffractometer, SENJU, which just became open for users, is the instrument designed to perform structure analyses under multiple extreme conditions even with tiny samples. Additional six detectors and T0 chopper were installed in order to improve the data collection efficiency and the background noise arises from the burst neutron. The solid angle covarage increased by 1.2 with the six new detectors, and significant reduction of the background noises were confirmed especially on the detectors at highest and lowest angles.
Fujihisa, Yui*; Takahashi, Miwako*; Hagihara, Masato; Torii, Shuki*; Kamiyama, Takashi*; Ohara, Takashi; Noda, Yukio*
no journal, ,
Takyu, Sodai*; Matsumoto, Kenichiro*; Hirade, Tetsuya; Nishikido, Fumihiko*; Akamatsu, Go*; Tashima, Hideaki*; Takahashi, Miwako*; Yamaya, Taiga*
no journal, ,
no abstracts in English
Tamura, Itaru; Oikawa, Kenichi; Takahashi, Miwako*; Kawasaki, Takuro*; Kimura, Hiroyuki*; Kiyanagi, Ryoji*; Ohara, Takashi; Kaneko, Koji; Kiyotani, Tamiko*; Arai, Masatoshi; et al.
no journal, ,
no abstracts in English
Oikawa, Kenichi; Kaneko, Koji; Tamura, Itaru; Ohara, Takashi; Kawasaki, Takuro; Kimura, Hiroyuki*; Noda, Yukio*; Takahashi, Miwako*; Kiyotani, Tamiko*; Kiyanagi, Ryoji*; et al.
no journal, ,
A new single crystal neutron diffractometer SENJU is now under construction at a high pace in MLF at J-PARC. SENJU will realize precise structure analysis under the combined extreme conditions such as high-magnetic field and low temperature. The construction will be completed at the end of 2010 fiscal year, and has aimed at the first beam acceptance before the summer of 2011. In the presentation, detailed instrument specs will be introduced, and a concrete sample environment etc. will be described.
Kawasaki, Takuro; Takahashi, Miwako; Ohara, Takashi*; Oshima, Kenichi*; Kusaka, Katsuhiro*; Tanaka, Ichiro*; Hosoya, Takaaki*; Yamada, Taro*; Kurihara, Kazuo; Niimura, Nobuo*
no journal, ,
Oikawa, Kenichi; Ohara, Takashi*; Kiyanagi, Ryoji; Kawasaki, Takuro; Tamura, Itaru; Kaneko, Koji; Nakamura, Tatsuya; Sakasai, Kaoru; Nakao, Akiko*; Hanashima, Takayasu*; et al.
no journal, ,
SENJU, named after the thousand armed Goddess of Mercy, is a single crystal time-of-flight Laue diffractometer proposed to the MLF at J-PARC. The diffractometer is dedicated for precise crystal and magnetic structure analyses under the combined extreme conditions using a small sample less than 1 . TOF-Laue technique coupled with wide area 2D detectors enables the efficient measurements and improves the completeness of the data. A WLSF-type scintillator detector developed for iBIX was modified to meet the requirements of SENJU. Although the construction schedule has been delayed because of the earthquake, on-beam commissioning will start in 2012.
Kawasaki, Takuro; Takahashi, Miwako*; Oshima, Kenichi*; Ohara, Takashi*; Tanaka, Ichiro*; Kusaka, Katsuhiro*; Hosoya, Takaaki*; Kurihara, Kazuo; Niimura, Nobuo*; Yamada, Taro*
no journal, ,
no abstracts in English
Kawasaki, Takuro; Oikawa, Kenichi; Ohara, Takashi*; Kiyanagi, Ryoji; Tamura, Itaru; Kaneko, Koji; Nakamura, Tatsuya; Sakasai, Kaoru; Nakao, Akiko*; Hanashima, Takayasu*; et al.
no journal, ,
no abstracts in English
Kiyanagi, Ryoji; Ohara, Takashi*; Kawasaki, Takuro; Oikawa, Kenichi; Tamura, Itaru; Kaneko, Koji; Hanashima, Takayasu*; Nakao, Akiko*; Munakata, Koji*; Kimura, Hiroyuki*; et al.
no journal, ,
no abstracts in English
Kawasaki, Takuro; Takahashi, Miwako*; Ohara, Takashi*; Kiyanagi, Ryoji; Oikawa, Kenichi; Tamura, Itaru; Kaneko, Koji; Nakao, Akiko*; Hanashima, Takayasu*; Munakata, Koji*
no journal, ,
no abstracts in English
Kiyanagi, Ryoji; Ohara, Takashi*; Kawasaki, Takuro; Oikawa, Kenichi; Tamura, Itaru; Kaneko, Koji; Nakao, Akiko*; Hanashima, Takayasu*; Munakata, Koji*; Kimura, Hiroyuki*; et al.
no journal, ,
no abstracts in English