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-, 
- and X-ray spectraOshima, Masumi*; Goto, Jun*; Hayakawa, Takehito*; Asai, Masato; Shinohara, Hirofumi*; Suzuki, Katsuyuki*; Shen, H.*
Journal of Nuclear Science and Technology, 10 Pages, 2025/00
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)The spectrum determination method (SDM) is the method to determine radioactivities by analyzing full spectral shape of - or rays through least-squares fitting by referring to standard - and spectra. In this paper, we have newly applied the SDM to a unified spectrum composed of two spectra measured with a Ge detector and a liquid scintillation counter. By analyzing the unified spectrum, uncertainties of deduced radioactivities have been improved. We applied this method to the unified spectrum including 40 radionuclides with equal intensities, and have deduced their radioactivities correctly.
Oshima, Masumi*; Goto, Jun*; Hayakawa, Takehito*; Shinohara, Hirofumi*; Suzuki, Katsuyuki*; Sano, Yuichi*; Asai, Masato; Haraga, Tomoko
Journal of Nuclear Science and Technology, 61(7), p.871 - 882, 2024/07
Times Cited Count：1 Percentile：27.70(Nuclear Science & Technology)Previously we reported a simple algorithmic method of spectral determination method (SDM), which is based on the first principle that a -ray spectrum obtained for a sample is a linear superposition of individual spectra of the radioactive nuclides included in the sample and demonstrated that the method is valid for -ray determination. Here we apply it to the spectra obtained by liquid scintillation counter (LSC). In LSC measurements quenching is generally observed and we at first developed its correction method to standard spectra. The SDM code reported in the previous investigation is used to analyze the LSC spectra. Based on the analyses done by using the measured spectra, we concluded that the SDM method is valid in the LSC spectra similarly to the -ray spectra studied in the previous investigation.
, , and X-ray spectrum analysisOshima, Masumi*; Goto, Jun*; Hayakawa, Takehito*; Asai, Masato; Kin, Tadahiro*; Shinohara, Hirofumi*
Isotope News, (790), p.19 - 23, 2023/12
When analyzing samples that contain many radionuclides at various concentrations, such as radioactive waste or fuel debris, it is difficult to apply general spectrum analysis methods and is necessary to chemically separate each nuclide before quantifying it. The chemical separation is especially essential for analysis using a liquid scintillation counter (LSC). In this report, the authors explain the newly developed spectral determination method (SDM) in which the entire spectrum is fitted to quantify radioactivity of nuclides mixed in a sample. By applying the SDM to - and X-ray spectrum measured by LSC and -ray spectrum measured by Ge detector simultaneously, the authors demonstrated that radioactivity of 40 radionuclides mixed in a sample at concentrations varying by two orders could be quantified, which is useful to simplify chemical separation process in radionuclide quantification.
Np and 
Am gamma ray regionsFukuda, Tatsuo; Kobata, Masaaki; Shobu, Takahisa; Yoshii, Kenji; Kamiya, Junichiro; Iwamoto, Yosuke; Makino, Takahiro*; Yamazaki, Yuichi*; Oshima, Takeshi*; Shirai, Yasuhiro*; et al.
Journal of Applied Physics, 132(24), p.245102_1 - 245102_8, 2022/12
Times Cited Count：1 Percentile：7.68(Physics, Applied)Direct energy conversion has been investigated using Ni/SiC Schottky junctions with the irradiation of monochromatized synchrotron X-rays simulating the gamma rays of Np (30 keV) and Am (60 keV). From current-voltage measurements, electrical energies were obtained for both kinds of gamma rays. The energy conversion efficiencies were found to reach up to 
1.6%, which is comparable to those of a few other semiconducting systems reported thus far. This result shows a possibility of energy recovery from nuclear wastes using the present system, judging from the radiation tolerant nature of SiC. Also, we found different conversion efficiencies between the two samples. This could be understandable from hard X-ray photoelectron spectroscopy and secondary ion mass spectroscopy measurements, suggesting the formation of Ni-Si compounds at the interface in the sample with a poor performance. Hence, such combined measurements are useful to provide information that cannot be obtained by electrical measurements alone.
At]NaAt and [
I]NaI in an NIS-expressing thyroid cancer mouse modelWatabe, Tadashi*; Liu, Y.*; Kaneda, Kazuko*; Sato, Tatsuhiko; Shirakami, Yoshifumi*; Oe, Kazuhiro*; Toyoshima, Atsushi*; Shimosegawa, Eku*; Wang, Y.*; Haba, Hiromitsu*; et al.
International Journal of Molecular Sciences (Internet), 23(16), p.9434_1 - 9434_11, 2022/08
Times Cited Count：12 Percentile：74.86(Biochemistry & Molecular Biology)In this study, we compare the therapeutic effect between [At]NaAt and [I]NaI. In vitro analysis of double-stranded DNA break (DSB) and colony formation assay were performed using K1-NIS cells. [At]NaAt induced higher numbers of DSBs and had a reduced colony formation than [I]NaI. In K1-NIS mice, dose-dependent therapeutic effects were observed in both [At]NaAt and [I]NaI. The superior therapeutic effect of [At]NaAt suggests the promising clinical applicability of targeted alpha therapy using [At]NaAt in patients with differentiated thyroid cancer refractory to standard [I]NaI treatment.
-ray detection to long-lived radioactive nuclide determination in environmental samplesOshima, Masumi*; Goto, Jun*; Haraga, Tomoko; Kin, Tadahiro*; Ikebe, Yurie*; Seto, Hirofumi*; Bamba, Shigeru*; Shinohara, Hirofumi*; Morimoto, Takao*; Isogai, Keisuke*
Journal of Nuclear Science and Technology, 57(6), p.663 - 670, 2020/06
Times Cited Count：1 Percentile：9.12(Nuclear Science & Technology)Gamma-gamma coincidence measurement utilized in -ray spectroscopy experiments is well known to be effective for the improvement of signal-to-noise ratio in a -ray spectrum. We study its applicability to determination of long-lived radioactive nuclides in environmental samples. The -ray simulation code Geant 4.10.2 was used. We took up 35 nuclides which need to be determined for the evaluation of fission product leakage at the nuclear accident in the Fukushima nuclear power plants. Among them five nuclides of 
Co, 
Nb, 
Cs, 
Eu and 
Eu can be the objectives of the multiple -ray detection method. The simulation results indicate that the signal-to-noise ratio can be improved by a factor between 9.8 and 283, and the detection limit by a factor between 2.7 and 8.5 relative to the singles measurement, implying that the method can be well applied to the determination of the long-lived radioactive nuclides.
Oshima, Masumi*; Yamaguchi, Yurie*; Asai, Masato; Tsukada, Kazuaki; Goto, Jun*; Bamba, Shigeru*; Bi, C.*; Morimoto, Takao*
Journal of Nuclear Science and Technology, 56(9-10), p.866 - 872, 2019/09
Times Cited Count：1 Percentile：8.95(Nuclear Science & Technology)Sensitivity of charged particle activation analysis with 8 MeV proton beam was studied for determination of 35 long-lived radioactive nuclides. Reaction cross sections for those nuclides were estimated with ALICE-91 code and isomer yield ratios were estimated from those of neighboring isotopes by taking into account their spins and parities. It was found that the proposed charged particle activation analysis should show high sensitivity for the determination of several hardly measurable nuclides with long half-lives such as 
Cs, 
Pu, 
I, 
Sn, 
Mo, 
Pd, 
U, 
Cm, and Np.
Onoda, Shinobu; Haruyama, Moriyoshi; Teraji, Tokuyuki*; Isoya, Junichi*; Kada, Wataru*; Hanaizumi, Osamu*; Oshima, Takeshi
Physica Status Solidi (A), 212(11), p.2641 - 2644, 2015/11
Times Cited Count：12 Percentile：45.24(Materials Science, Multidisciplinary)Haruyama, Moriyoshi; Onoda, Shinobu; Kada, Wataru*; Teraji, Tokuyuki*; Isoya, Junichi*; Oshima, Takeshi; Hanaizumi, Osamu*
Proceedings of 11th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-11) (Internet), p.184 - 187, 2015/11
Iwai, Yasunori; Kubo, Hitoshi*; Oshima, Yusuke*; Noguchi, Hiroshi*; Edao, Yuki; Taniuchi, Junichi*
Fusion Science and Technology, 68(3), p.596 - 600, 2015/10
Times Cited Count：2 Percentile：16.23(Nuclear Science & Technology)We have newly developed the hydrophobic platinum honeycomb catalysts applicable to tritium oxidation reactor since the honeycomb-shape catalyst can decrease the pressure drop. Two types of hydrophobic honeycomb catalyst have been test-manufactured. One is the hydrophobic platinum catalyst on a metal honeycomb. The other is the hydrophobic platinum catalyst on a ceramic honeycomb made of silicon carbide. The fine platinum particles around a few nanometers significantly improve the catalytic activity for the oxidation tritium at a tracer concentration. The hydrogen concentration in the gaseous feed slightly affects the overall reaction rate constant for hydrogen oxidation. Due to the competitive adsorption of hydrogen and water molecules on platinum surface, the overall reaction rate constant has the bottom value. The hydrogen concentration for the bottom value is 100 ppm under the dry feed gas. We have experimentally confirmed the activity of these honeycomb catalysts is as good as that of pellet-shape hydrophobic catalyst. The results support the hydrophobic honeycomb catalysts are applicable to tritium oxidation reactor.
SGo, 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
Iwai, Yasunori; Kubo, Hitoshi*; Sato, Katsumi; Oshima, Yusuke*; Noguchi, Hiroshi*; Taniuchi, Junichi*
Proceedings of 7th Tokyo Conference on Advanced Catalytic Science and Technology (TOCAT-7) (USB Flash Drive), 2 Pages, 2014/06
Hydrophobic platinum catalysts have been developed especially for combustion of hydrogen isotopes released in a nuclear facility. A new type of hydrophobic hydrogen combustion catalyst commercially named TKK-KNOITS catalyst is hardly susceptible to water mist and water vapor in the atmosphere and water produced by hydrogen combustion. It is capable of maintaining the activity even at relatively low temperatures. The TKK-KNOITS catalyst is superior to other previous hydrophobic catalysts in applicability to wide range of hydrogen concentration from very thin to dense. The catalyst which carrier is composed of inorganic oxide has thermal stability up to 873 K.
rays from the neutron resonances of 
Se and 
Se at the J-PARC/MLF/ANNRIHori, Junichi*; Yashima, Hiroshi*; Nakamura, Shoji; Furutaka, Kazuyoshi; Hara, Kaoru; Harada, Hideo; Hirose, Kentaro; Kimura, Atsushi; Kitatani, Fumito; Koizumi, Mitsuo; et al.
Nuclear Data Sheets, 119, p.128 - 131, 2014/05
Times Cited Count：4 Percentile：31.51(Physics, Nuclear)In this work, we measured the capture rays from the neutron resonances of Se and Se. A neutron time-of-flight method was adopted for the measurements with a 4
Ge spectrometer installed at the Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) in the J-PARC Material and Life science experimental Facility (MLF). The -ray pulse-height spectra corresponding to the 27-eV resonance of Se and the 113-, 212-, 291-, 342-, 690- and 864-eV resonances of Se were obtained by gating on the TOF regions, respectively. The relative intensities of those primary transitions were derived and compared with the previous experimental data. For the 27-eV resonance of Se, a strong primary transition to the 293-keV state was observed. As for Se, the quite differences of the decay pattern were found between the resonances.
Pd and stable 
Pd nuclei at J-PARC/MLF/ANNRINakamura, Shoji; Kimura, Atsushi; Kitatani, Fumito; Ota, Masayuki; Furutaka, Kazuyoshi; Goko, Shinji*; Hara, Kaoru; Harada, Hideo; Hirose, Kentaro; Kin, Tadahiro*; et al.
Nuclear Data Sheets, 119, p.143 - 146, 2014/05
Times Cited Count：10 Percentile：55.29(Physics, Nuclear)We have started the measurements of the neutron-capture cross sections for stable Pd nuclei as well as the radioactive Pd. The neutron-capture cross-section measurements by the time-of flight method were performed using an apparatus called "Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI)" installed at the neutron Beam Line No.4 of the Materials and Life science experimental Facility (MLF) in the J-PARC. The neutron-capture cross sections of Pd and Pd have been measured in the neutron energy range from thermal to 300 eV. Some new information was obtained for resonances of these Pd nuclei.
Np
at J-PARC/MLF/ANNRIHirose, Kentaro; Furutaka, Kazuyoshi; Hara, Kaoru; Harada, Hideo; Hori, Junichi*; Igashira, Masayuki*; Kamiyama, Takashi*; Katabuchi, Tatsuya*; Kimura, Atsushi; Kin, Tadahiro*; et al.
Nuclear Data Sheets, 119, p.48 - 51, 2014/05
Times Cited Count：1 Percentile：9.69(Physics, Nuclear)Am(n,) at J-PARC/MLF/ANNRIHarada, Hideo; Ota, Masayuki; Kimura, Atsushi; Furutaka, Kazuyoshi; Hirose, Kentaro; Hara, Kaoru; Kin, Tadahiro*; Kitatani, Fumito; Koizumi, Mitsuo; Nakamura, Shoji; et al.
Nuclear Data Sheets, 119, p.61 - 64, 2014/05
Times Cited Count：19 Percentile：74.32(Physics, Nuclear)Son, N. T.*; Isoya, Junichi*; Ivanov, I. G.*; Oshima, Takeshi; Janz
n, E.*
AIP Conference Proceedings 1583, p.341 - 344, 2014/02
Waldherr, G.*; Wang, Y.*; Zaiser, S.*; Jamali, M.*; Schulte-Herbr
ggen, T.*; Abe, Hiroshi; Oshima, Takeshi; Isoya, Junichi*; Du, J. F.*; Neumann, P.*; et al.
Nature, 506(7487), p.204 - 207, 2014/02
Times Cited Count：467 Percentile：99.58(Multidisciplinary Sciences)no abstracts in English
Kino, Koichi*; Furusaka, Michihiro*; Hiraga, Fujio*; Kamiyama, Takashi*; Kiyanagi, Yoshiaki*; Furutaka, Kazuyoshi; Goko, Shinji*; Hara, Kaoru; Harada, Hideo; Harada, Masahide; et al.
Nuclear Instruments and Methods in Physics Research A, 736, p.66 - 74, 2014/02
Times Cited Count：32 Percentile：90.83(Instruments & Instrumentation)
Sn using ANNRI-NaI(Tl) spectrometer at J-PARCHirose, Kentaro; Furutaka, Kazuyoshi; Hara, Kaoru; Harada, Hideo; Kimura, Atsushi; Kitatani, Fumito; Koizumi, Mitsuo; Nakamura, Shoji; Oshima, Masumi; Toh, Yosuke; et al.
JAEA-Conf 2013-002, p.173 - 178, 2013/10
