Tsukada, Kazuaki; Nagai, Yasuki*; Hashimoto, Shintaro; Minato, Futoshi; Kawabata, Masako*; Hatsukawa, Yuichi*; Hashimoto, Kazuyuki*; Watanabe, Satoshi*; Saeki, Hideya*; Motoishi, Shoji*
Journal of the Physical Society of Japan, 89(3), p.034201_1 - 034201_7, 2020/03
We found anomalously large yields of Ga, Ga, Zn and Cu by neutron irradiation on a ZnO sample in a polyethylene shield. Neutron beams are generated from the Be() reaction for 50 MeV deuterons. The yields obtained were more than 20 times larger than those in the unshielded sample. On the other hand, the yields of Ga, Ga, Zn and Cu from a metallic Zn sample and the yields of Cu, Ni and Zn from the ZnO and Zn samples were almost insensitive to the shield conditions. This finding would provide us a unique capability of accelerator neutrons to simultaneously produce a large amount of several radioisotopes, including proton induced reaction products, by using a single sample. The experimental data were compared with the yields estimated by using the Particle and Heavy Ion Transport code System and the result was discussed.
Hatsukawa, Yuichi*; Hayakawa, Takehito*; Tsukada, Kazuaki; Hashimoto, Kazuyuki*; Sato, Tetsuya; Asai, Masato; Toyoshima, Atsushi; Tanimori, Toru*; Sonoda, Shinya*; Kabuki, Shigeto*; et al.
PLOS ONE (Internet), 13(12), p.e0208909_1 - e0208909_12, 2018/12
Imaging of Tc radioisotope was conducted using an electron tracking-Compton camera (ETCC). Tc emits 204, 582, and 835 keV rays, and was produced in the Mo(p,n)Tc reaction with a Mo-enriched target. The recycling of the Mo-enriched molybdenum trioxide was investigated, and the recycled yield of Mo was achieved to be 70% - 90%. The images were obtained with each of the three rays. Results showed that the spatial resolution increases with increasing -ray energy, and suggested that the ETCC with high-energy -ray emitters such as Tc is useful for the medical imaging of deep tissue and organs in the human body.
Sugawara, Masahiko*; Toh, Yosuke; Koizumi, Mitsuo; Oshima, Masumi*; Kimura, Atsushi; Kin, Tadahiro*; Hatsukawa, Yuichi*; Kusakari, Hideshige*
Physical Review C, 96(2), p.024314_1 - 024314_7, 2017/08
Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Kobayashi, Motoki*; Kisamori, Keiichi*; Takaki, Motonobu*; Miya, Hioyuki*; Ota, Shinsuke*; Michimasa, Shinichiro*; Shimoura, Susumu*; et al.
JPS Conference Proceedings (Internet), 6, p.030005_1 - 030005_4, 2015/06
Hashimoto, Kazuyuki; Nagai, Yasuki; Kawabata, Masako; Sato, Nozomi*; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji*; Ota, Masayuki; Konno, Chikara; Ochiai, Kentaro; et al.
Journal of the Physical Society of Japan, 84(4), p.043202_1 - 043202_4, 2015/04
Hatsukawa, Yuichi; Hashimoto, Kazuyuki; Tsukada, Kazuaki; Sato, Tetsuya; Asai, Masato; Toyoshima, Atsushi; Nagai, Yasuki; Tanimori, Toru*; Sonoda, Shinya*; Kabuki, Shigeto*; et al.
Journal of Radioanalytical and Nuclear Chemistry, 303(2), p.1283 - 1285, 2015/02
Technetium-99m (Tc) is used in radioactive medical diagonostic tests, for example as a radioactive tracer that medical equipment can detect in the human body. It is well suited to the role because it emits readily detectable 141 keV rays, and its half-life is 6.01 hours (meaning that about 94% of it decays to technetium-99 in 24 hours). There are at least 31 commonly used radiopharmaceuticals based on technetium-99m for imaging and functional studies of the brain, myocardium, thyroid, lungs, liver, gallbladder, kidneys, skeleton, blood, and tumors. Recent years, with the develop-ment of the Compton camera which can realize high position resolution, technetium isotopes emitting high energy -rays are required. In this study, technetium-95m which emits some rays around 800 keV was produced by the Mo(p,n)Tc reaction.
Osawa, Takahito; Hatsukawa, Yuichi
Ningen Seikatsu Bunka Kenkyu (Internet), (25), p.221 - 230, 2015/00
Segawa, Mariko; Toh, Yosuke; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Fukahori, Tokio; Oshima, Masumi*; Iwamoto, Nobuyuki; Iwamoto, Osamu; Hatsukawa, Yuichi; et al.
AIP Conference Proceedings 1594, p.339 - 344, 2014/05
Li, G. S.*; Liu, M. L.*; Zhou, X. H.*; Zhang, Y. H.*; Liu, Y. X.*; Zhang, N. T.*; Hua, W.*; Zheng, Y. D.*; Fang, Y. D.*; Guo, S.*; et al.
Physical Review C, 89(5), p.054303_1 - 054303_9, 2014/05
High-spin states of Pt have been reinvestigated using the Yb(O, 4) reaction at a beam energy of 88 MeV. The previously known positive parity band associated with the ( being or ) configuration has been revised and extended significantly. A new negative parity band has been established and proposed to be based on the configuration. Possible structure evolution of the yrast line from predominantly vibrational to rotational with increasing spin is discussed with the help of E over spin curves. Additionally, calculations of Total Routhian surfaces have been performed to investigate the band properties.
Nagai, Yasuki; Hashimoto, Kazuyuki; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji; Sonoda, Nozomi; Kawabata, Masako; Harada, Hideo; Kin, Tadahiro*; Tsukada, Kazuaki; et al.
Journal of the Physical Society of Japan, 82(6), p.064201_1 - 064201_7, 2013/06
Kin, Tadahiro*; Nagai, Yasuki; Iwamoto, Nobuyuki; Minato, Futoshi; Iwamoto, Osamu; Hatsukawa, Yuichi; Segawa, Mariko; Harada, Hideo; Konno, Chikara; Ochiai, Kentaro; et al.
Journal of the Physical Society of Japan, 82(3), p.034201_1 - 034201_8, 2013/03
We have measured the activation cross sections producing Cu and Cu, promising medical radioisotopes for molecular imaging and radioimmunotherapy, by bombarding a natural zinc sample with 14 MeV neutrons. We estimated the production yields of Cu and Cu by fast neutrons from C(d,n) with 40 MeV 5 mA deuterons. The calculated Cu yield is 1.8 TBq (175 g Zn) for 12 h of irradiation; the yields of Cu by Zn(n,p)Cu and Zn(n,x)Cu were 249 GBq (184 g Zn) and 287 GBq (186 g Zn) at the end of 2 days of irradiation, respectively. From the results, we proposed a new route to produce Cu with very little radionuclide impurity via the Zn(n,x)Cu reaction, and showed the Zn(n,p)Cu reaction to be a promising route to produce Cu.
He, C.*; Shen, S.*; Wen, S.*; Zhu, L.*; Wu, X.*; Li, G.*; Zhao, Y.*; Yan, Y.*; Bai, Z.*; Wu, Y.*; et al.
Physical Review C, 87(3), p.034320_1 - 034320_10, 2013/03
Onoue, Tetsuji*; Sato, Honami*; Nakamura, Tomoki*; Noguchi, Takaaki*; Hidaka, Yoshihiro*; Shirai, Naoki*; Ebihara, Mitsuru*; Osawa, Takahito; Hatsukawa, Yuichi; Toh, Yosuke; et al.
Proceedings of the National Academy of Sciences of the United States of America, 109(47), p.19134 - 19139, 2012/11
The 34 million year (My) interval of the Late Triassic is marked by the formation of several large impact structures on Earth. As with the Chicxulub impact event at the Cretaceous/Paleogene boudary, the Late Triassic impact events have been considered a factor in biotic extinction events in the Late Triassic (e.g., the Triassic/Jurassic boundary). However, the causal link between these impact events and a mass extinction event in the Late Triassic remains controversial because of a lack of stratigraphic records of their ejecta deposits. Here we report evidence for an impact event (platinum group elements anomaly, nickel-rich magnetite and microspherules) deposited within a Paleo-Pacific basin in the middle Norian (Upper Triassic) deep-sea sediment in Japan. This includes anomalously high abundances of iridium, up to 41.5 parts per billion (ppb), in the ejecta deposit, which suggests that the iridium anomaly may be found on a global scale. The middle Norian age of the ejecta deposit suggests that the impact event that produced the 100-km-wide Manicouagan crater in Canada8 is most likely related to its deposition. Our analysis of siliceous microfossils shows no evidence of a mass extinction event across the impact event horizon, and no contemporaneous faunal turnover is seen in other marine fossils. However, such an event has been reported among terrestrial tetrapods and floras in North America. We therefore hypothesize that the Manicouagan impact caused the catastrophic collapse of terrestrial ecosystems near the impact site, but not within the marine realm.
Wang, H. X.*; Zhang, Y. H.*; Zhou, X. H.*; Liu, M. L.*; Ding, B.*; Li, G. S.*; Hua, W.*; Zhou, H. B.*; Guo, S.*; Qiang, Y. H.*; et al.
Physical Review C, 86(4), p.044305_1 - 044305_11, 2012/10
Ideguchi, Eiji*; Ota, Shinsuke*; Morikawa, Tsuneyasu*; Oshima, Masumi; Koizumi, Mitsuo; Toh, Yosuke; Kimura, Atsushi; Harada, Hideo; Furutaka, Kazuyoshi; Nakamura, Shoji; et al.
Progress of Theoretical Physics Supplement, (196), p.427 - 432, 2012/10
Sugawara, Masahiko*; Hayakawa, Takehito; Oshima, Masumi*; Toh, Yosuke; Osa, Akihiko; Matsuda, Makoto; Shizuma, Toshiyuki; Hatsukawa, Yuichi; Kusakari, Hideshige*; Morikawa, Tsuneyasu*; et al.
Physical Review C, 86(3), p.034326_1 - 034326_11, 2012/09
High spin states of Pd have been studied through in-beam -ray spectroscopy by using the reaction Zn (Cl, 13). The band based on the neutron orbital has been extended to higher-spin states, and the band based on the neutron orbital has been somewhat revised. Many transitions decaying to these bands have been observed and consequently, several side bands have been established. Electric dipole transitions from the band to the band have been also observed. The structure of the band was discussed from the viewpoint of "antimagnetic rotation" based on a semiclassical particle plus rotor model taking neutron alignments into account.
Hatsukawa, Yuichi; Osawa, Takahito; Oshima, Masumi; Toh, Yosuke; Kimura, Atsushi; Koizumi, Mitsuo; Furutaka, Kazuyoshi
Journal of Radioanalytical and Nuclear Chemistry, 291(1), p.143 - 145, 2012/01
The Ir concentrations in some standard rock samples were determined by using the multiple ray detection method. The use of the multiple ray detection method, which was developed for nuclide quantification, yielded better resolution and sensitivity than the ordinary singles ray detection method. Iridium is one of the least abundant elements in Earth's crust, with an average mass fraction of 0.001 ppm in a crust rock. However, iridium is relatively more abundant (concentration: 0.5 ppm or more) in undifferentiated meteorites. Therefore iridium abundance anomalies in geological samples provide important information about meteorite impact. The standard rock samples used in this study were SARM-76, FC-1 and FC-2. The SARM-76 was prepared from a platinum ore, and issued by the South African Bureau of Standards. FC-1 and FC-2 were obtained from fish clay sediment samples from Stevens Klint, Denmark.
Appel, P.*; Na-Oy, L.*; Hatsukawa, Yuichi; Osawa, Takahito; Kystol, J.*; Srensen, L.*
Danmarks og Grnlands Geologiske Undersgelse Rapport, Vol.127, 39 Pages, 2011/12
This report presents the results of experiments involving the revival of an old method for removal of mercury from tailings after gold extraction by small-scale miners. Numerous tailings from small-scale gold mining are found throughout the Philippines. The tailings have proved to contain large amounts of mercury (up to 250 gram per ton). Furthermore, the tailings contain large amounts of gold locked-up in the mercury - up to 16 gram per ton. The mercury occurs as mercury flour (globules less than a millimetre across). Mercury flour is produced through milling of gold ore, when the mercury is added to tailling drums (whole ore amalgamation). The globules "hidden" in the mercury flour cannot be recovered by small-scale gold miners in any environmentally benign ways.
Zhou, H. B.*; Zhou, X. H.*; Zhang, Y. H.*; Zheng, Y.*; Liu, M. L.*; Zhang, N. T.*; Chen, L.*; Wang, S. T.*; Li, G. S.*; Wang, H. X.*; et al.
European Physical Journal A, 47(9), p.107_1 - 107_7, 2011/09
High-spin states in Pd have been investigated by means of in-beam -ray spectroscopic techniques. The previously known and 1/2 bands were extended to higher spins. The band crossings observed experimentally are explained by the alignment of protons. The band properties in Pd are compared with those in the neighboring nuclei and are discussed within the framework of the cranked shell model.
Li, G. S.*; Zhou, X. H.*; Zhang, Y. H.*; Zheng, Y.*; Liu, M. L.*; Hua, W.*; Zhou, H. B.*; Ding, B.*; Wang, H. X.*; Lei, X. G.*; et al.
Journal of Physics G; Nuclear and Particle Physics, 38(9), p.095105_1 - 095105_9, 2011/09
High-spin states in Pt have been investigated by means of in beam -ray spectroscopic method at the JAEA tandem facility. Low-spin signature inversion is revealed in the 7/2 band. The inversion can be interpreted as a configuration change from the 7/2 orbital to the 7/2 orbital with increasing spin, which is supported by a theoretical calculation of the semi-classical Donau and Frauendorf approach.