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Journal Articles

Integral experiment of $$^{129}$$I(n, $$gamma$$) using fast neutron source in the "YAYOI" reactor

Nakamura, Shoji; Toh, Yosuke; Kimura, Atsushi; Hatsukawa, Yuichi*; Harada, Hideo

Journal of Nuclear Science and Technology, 59(7), p.851 - 865, 2022/07

The present study performed integral experiments of $$^{129}$$I using a fast-neutron source reactor "YAYOI" of the University of Tokyo to validate evaluated nuclear data libraries. The iodine-129 sample and flux monitors were irradiated by fast neutrons in the Glory hole of the YAYOI reactor. Reaction rates of $$^{129}$$I were obtained by measurement of decay gamma-rays emitted from $$^{130}$$I. The validity of the fast-neutron flux spectrum in the Glory hole was confirmed by the ${it C/E}$ ratios of the reaction rates of flux monitors. The experimental reaction rate of $$^{129}$$I was compared with that calculated with both the fast-neutron flux spectrum and evaluated nuclear data libraries. The present study revealed that the evaluated nuclear data of $$^{129}$$I cited in JENDL-4.0 should be reduced as much as 18% in neutron energies ranging from 10 keV to 3 MeV, and supported the reported data by Noguere ${it et al.}$ below 100 keV.

Journal Articles

Integral experiments of technetium-99 using fast-neutron source reactor "YAYOI"

Nakamura, Shoji; Hatsukawa, Yuichi*; Kimura, Atsushi; Toh, Yosuke; Harada, Hideo

Journal of Nuclear Science and Technology, 58(12), p.1318 - 1329, 2021/12

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

The present study performed fast-neutron capture cross-section measurement of $$^{99}$$Tc by an activation method using a fast-neutron source reactor "YAYOI" of the University of Tokyo. Technetium-99 samples were irradiated with reactor neutrons using a pneumatic system. Reaction rates of $$^{99}$$Tc were obtained by measuring decay gamma rays emitted from $$^{100}$$Tc. The neutron flux at an irradiation position was monitored with gold foils. The fast-neutron capture cross section of $$^{99}$$Tc at neutron energy of 85 keV was derived as 0.432$$pm$$0.023 barn by using the reaction rates of $$^{99}$$Tc, evaluated cross-section data and the fast-neutron flux spectrum of the YAYOI reactor. The present study agreed with the evaluated nuclear data library JENDL-4.0.

Journal Articles

High-spin states in $$^{35}$$S

Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Aoi, Nori*; Azaiez, F.*; Furutaka, Kazuyoshi; Hatsukawa, Yuichi; Kimura, Atsushi; Kisamori, Keiichi*; Kobayashi, Motoki*; et al.

Physical Review C, 103(3), p.034327_1 - 034327_8, 2021/03

 Times Cited Count:0 Percentile:0.03(Physics, Nuclear)

Journal Articles

Electron-tracking Compton camera imaging of technetium-95m

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


 Times Cited Count:0 Percentile:0.01(Multidisciplinary Sciences)

Imaging of $$^{95m}$$Tc radioisotope was conducted using an electron tracking-Compton camera (ETCC). $$^{95m}$$Tc emits 204, 582, and 835 keV $$gamma$$ rays, and was produced in the $$^{95}$$Mo(p,n)$$^{95m}$$Tc reaction with a $$^{95}$$Mo-enriched target. The recycling of the $$^{95}$$Mo-enriched molybdenum trioxide was investigated, and the recycled yield of $$^{95}$$Mo was achieved to be 70% - 90%. The images were obtained with each of the three $$gamma$$ rays. Results showed that the spatial resolution increases with increasing $$gamma$$-ray energy, and suggested that the ETCC with high-energy $$gamma$$-ray emitters such as $$^{95m}$$Tc is useful for the medical imaging of deep tissue and organs in the human body.

Journal Articles

Intermediate-spin states of $$^{92}$$Zr and a large $$B(E2)$$ value between the $$10_1^+$$ and $$8_1^+$$ states

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

 Times Cited Count:1 Percentile:14.2(Physics, Nuclear)

Journal Articles

Temperature of thermal spikes in amorphous silicon nitride films produced by 1.11 MeV C$$_{60}^{3+}$$ impacts

Kitayama, Takumi*; Nakajima, Kaoru*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Matsuda, Makoto; Sataka, Masao*; Tsujimoto, Masahiko*; Isoda, Shoji*; Kimura, Kenji*

Nuclear Instruments and Methods in Physics Research B, 354, p.183 - 186, 2015/07

 Times Cited Count:2 Percentile:22.25(Instruments & Instrumentation)

Journal Articles

Superdeformation in $$^{35}$$S

Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Kobayashi, Motoki*; Kisamori, Keiichi*; Takaki, Motonobu*; Miya, Hiroyuki*; Ota, Shinsuke*; Michimasa, Shinichiro*; Shimoura, Susumu*; et al.

JPS Conference Proceedings (Internet), 6, p.030005_1 - 030005_4, 2015/06

Journal Articles

Production of $$^{rm 95m}$$Tc for Compton camera imaging

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

 Times Cited Count:2 Percentile:22.25(Chemistry, Analytical)

Technetium-99m ($$^{rm 99m}$$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 $$gamma$$ 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 $$gamma$$-rays are required. In this study, technetium-95m which emits some $$gamma$$ rays around 800 keV was produced by the $$^{95}$$Mo(p,n)$$^{rm 95m}$$Tc reaction.

Journal Articles

Sputtering of SiN films by 540 keV C$$_{60}$$$$^{2+}$$ ions observed using high-resolution Rutherford backscattering spectroscopy

Nakajima, Kaoru*; Morita, Yosuke*; Kitayama, Takumi*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Tsujimoto, Masahiko*; Isoda, Shoji*; Fujii, Yoshikazu*; Kimura, Kenji*

Nuclear Instruments and Methods in Physics Research B, 332, p.117 - 121, 2014/08

 Times Cited Count:7 Percentile:55.77(Instruments & Instrumentation)

Journal Articles

Transmission secondary ion mass spectrometry using 5 MeV C$$_{60}$$$$^{+}$$ ions

Nakajima, Kaoru*; Nagano, Kengo*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Hirata, Koichi*; Kimura, Kenji*

Applied Physics Letters, 104(11), p.114103_1 - 114103_4, 2014/03

 Times Cited Count:5 Percentile:26.55(Physics, Applied)

Journal Articles

Occurrence and potential activity of denitrifiers and methanogens in groundwater at 140 m depth in Pliocene diatomaceous mudstone of northern Japan

Katsuyama, Chie*; Nashimoto, Hiroaki*; Nagaosa, Kazuyo*; Ishibashi, Tomotaka*; Furuta, Kazuki*; Kinoshita, Takeshi*; Yoshikawa, Hideki; Aoki, Kazuhiro; Asano, Takahiro*; Sasaki, Yoshito; et al.

FEMS Microbiology Ecology, 86(3), p.532 - 543, 2013/12

 Times Cited Count:8 Percentile:26.35(Microbiology)

Anaerobic microbial activity has a major influence on the subsurface environment, and should be considered in subsurface activities including the construction of radioactive waste repositories. We investigated denitrification and methanogenesis in anoxic groundwater from 140 m depth in two boreholes, where the redox potential fluctuated. The average maximum potential denitrification rates, measured under anaerobic conditions in the two boreholes using an $$^{15}$$N tracer. Methanogenesis candidates were detected by 16S rRNA gene analysis. Although the stable isotope signatures suggested that some of the dissolved methane was of biogenic origin, no potential for methane production was evident during the incubations. The groundwater at 140 m depth did not contain oxygen, had an Eh ranging from -144 to 6.8 mV, and was found to be a potential field for denitrification.

Journal Articles

Surface effect on ion track formation in amorphous Si$$_{3}$$N$$_{4}$$ films

Morita, Yosuke*; Nakajima, Kaoru*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Ishikawa, Norito; Hojo, Kiichi; Tsujimoto, Masahiko*; Isoda, Shoji*; Kimura, Kenji*

Nuclear Instruments and Methods in Physics Research B, 315, p.142 - 145, 2013/11

 Times Cited Count:8 Percentile:59.34(Instruments & Instrumentation)

Journal Articles

Cluster effect on projected range of 30-keV C$$_{60}$$$$^{+}$$ in silicon

Morita, Yosuke*; Nakajima, Kaoru*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Kimura, Kenji*

JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 167, 2013/01

no abstracts in English

Journal Articles

Direct observation of fine structure in ion tracks in amorphous Si$$_{3}$$N$$_{4}$$ by TEM

Nakajima, Kaoru*; Morita, Yosuke*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Ishikawa, Norito; Hojo, Kiichi; Tsujimoto, Masahiko*; Isoda, Shoji*; Kimura, Kenji*

Nuclear Instruments and Methods in Physics Research B, 291, p.12 - 16, 2012/11

 Times Cited Count:12 Percentile:69.17(Instruments & Instrumentation)

Thin films of amorphous Si$$_{3}$$N$$_{4}$$ (thickness 20 nm) were irradiated with 120-720 keV C$$_{60}$$$$^{+,2+}$$ ions and observed using transmission electron microscopy (TEM). The ion track produced in an amorphous material was directly observed by TEM. For quantitative analysis, the ion tracks were also observed using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM). The observed ion track consists of a low density core (radius $$sim$$2.5 nm) and a high density shell (width $$sim$$2.5 nm), which is very similar to the ion tracks in amorphous SiO$$_{2}$$ irradiated with high energy heavy ions observed by small angle X-ray scattering (SAXS). Although the observed ion tracks may be affected by surface effects, the present result indicates that TEM and HAADF-STEM have potential to observe directly the fine structures of ion tracks in amorphous materials.

Journal Articles

Rotational band properties of $$^{173}$$W

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


 Times Cited Count:5 Percentile:36.05(Physics, Nuclear)

Journal Articles

Superdeformed band in asymmetric N $$>$$ Z nucleus, $$^{40}$$Ar and high-spin states in A = 30 $$sim$$ 40 nuclei

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

Journal Articles

Measurements of Ir concentration in geological standard samples using neutron activation analysis with multiple $$gamma$$-ray coincidence method

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

 Times Cited Count:1 Percentile:11.68(Chemistry, Analytical)

The Ir concentrations in some standard rock samples were determined by using the multiple $$gamma$$ ray detection method. The use of the multiple $$gamma$$ ray detection method, which was developed for nuclide quantification, yielded better resolution and sensitivity than the ordinary singles $$gamma$$ 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.

Journal Articles

Development of high density MoO$$_{3}$$ pellets for production of $$^{99}$$Mo medical isotope

Kimura, Akihiro; Sato, Yuichi*; Tanase, Masakazu*; Tsuchiya, Kunihiko

IOP Conference Series; Materials Science and Engineering, 18(4), p.042001_1 - 042001_4, 2011/10

In the medical field, the radioisotopes are indispensable. Especially, $$^{99m}$$Tc is most commonly used as a radiopharmaceutical. However, the supply of $$^{99}$$Mo in Japan depends fully on the import from foreign countries. JMTR has a plan to produce a medical isotope of $$^{99}$$Mo, the parent nuclide of $$^{99m}$$Tc by the (n,$$gamma$$) method and a part of the import volume can be covered of the home country. In this plan, it is important to develop the production method of the irradiation targets such as the Molybdenum oxide (MoO$$_{3}$$) pellets. However, MoO$$_{3}$$ is low sublime temperature and it is difficult to produce the pellets with high density. In this study, MoO$$_{3}$$ pellets were produced by two kinds of production methods. As a result, MoO$$_{3}$$ pellet of about 70% TD was obtained by CIP and MoO$$_{3}$$ pellet of over 95% TD was obtained by SPS.

Journal Articles

Cluster effect on projected range of 30 keV C$$_{60}$$$$^{+}$$ in silicon

Morita, Yosuke*; Nakajima, Kaoru*; Suzuki, Motofumi*; Narumi, Kazumasa; Saito, Yuichi; Vandervorst, W.*; Kimura, Kenji*

Nuclear Instruments and Methods in Physics Research B, 269(19), p.2080 - 2083, 2011/10

 Times Cited Count:6 Percentile:48.42(Instruments & Instrumentation)

Pre-amorphized silicon wafers are implanted with 30 keV C$$_{60}$$$$^{+}$$ and 0.5 keV C$$^{+}$$ ions at room temperature with fluences about 2$$times$$10$$^{15}$$ atoms/cm$$^{2}$$. The depth profiles of implanted carbon are measured using high-resolution Rutherford backscattering spectroscopy. The observed average depth of C for the C$$_{60}$$$$^{+}$$ implantation is 6.1 nm while that for the C$$^{+}$$ implantation is 4.0 nm, showing a large cluster effect on the projected range.

JAEA Reports

Development of $$^{rm 99m}$$Tc extraction techniques from $$^{99}$$Mo by (n,$$gamma$$) reaction

Kimura, Akihiro; Hori, Naohiko; Tsuchiya, Kunihiko; Ishihara, Masahiro; Yamabayashi, Hisamichi*; Tanase, Masakazu*; Fujisaki, Saburo*; Sato, Yuichi*

JAEA-Review 2010-053, 23 Pages, 2010/11


Production techniques of $$^{99}$$Mo, parent nuclide of $$^{rm 99m}$$Tc, have been developed for the industrial utilization as medical diagnosis medicine after the JMTR refurbishment. The (n,$$gamma$$) method is proposed in JMTR because of low-amount radioactive wastes and easy $$^{rm 99m}$$Tc production process. In this study, the production of the high-density MoO$$_{3}$$ pellet and concentration techniques of $$^{rm 99m}$$Tc solution were developed. As the trial test, the MoO$$_{3}$$ pellets with high density were produced by the SPS (Spark Plasma Sintering) method. On the other hands, it was possible to concentrate $$^{rm 99m}$$Tc solution by the solvent extraction using Methyl Ethyl Ketone (MEK). From the result, the $$^{rm 99m}$$Tc concentrating device with more than 80% concentration efficiency, was performed successfully.

127 (Records 1-20 displayed on this page)