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Journal Articles

Measurement of the neutron capture cross section of $$^{185}$$Re in the keV energy region

Katabuchi, Tatsuya*; Sato, Yaoki*; Takebe, Karin*; Igashira, Masayuki*; Umezawa, Seigo*; Fujioka, Ryo*; Saito, Tatsuhiro*; Iwamoto, Nobuyuki

Journal of Nuclear Science and Technology, 6 Pages, 2024/00

 Times Cited Count:0 Percentile:0.18(Nuclear Science & Technology)

Journal Articles

Neutron capture cross-section measurements with TC-Pn in KUR for some nuclides targeted for decommissioning

Nakamura, Shoji; Endo, Shunsuke; Kimura, Atsushi; Shibahara, Yuji*

KURNS Progress Report 2022, P. 73, 2023/07

The present study is concerned with the neutron capture cross-sections that contribute to the evaluation of the amount of radionuclides possessing problems in decommissioning. In this study, $$^{45}$$Sc, $$^{63}$$Cu, $$^{64}$$Zn, $$^{109}$$Ag, $$^{113}$$In and $$^{186}$$W were selected among the objective nuclides, and their thermal-neutron capture cross-sections were measured using TC-Pn equipment of the KUR of the Institute for Integrated Radiation and Nuclear Science, Kyoto University. High purity metal samples were prepared. A gold-aluminum ally wire, cobalt and molybdenum foils were used to monitor the neutron flux at the irradiation position of TC-Pn. The flux monitors and metal samples were irradiated for 1 hour at 1-MW operation of the KUR. After irradiation, the irradiation capsule was opened, samples and flux monitors were enclosed in a vinyl bag one by one, and then $$gamma$$ rays emitted from the samples and monitors were measured with a high-purity Ge detector. The thermal-neutron flux component was derived with the reaction rates of flux monitors ($$^{197}$$Au, $$^{59}$$Co and $$^{98}$$Mo) on the basis of Westcott's convention, and found to be (5.92$$pm$$0.10)$$times$$10$$^{10}$$ n/cm$$^{2}$$/sec at the irradiation position. The measured reaction rate for each metal sample divided by the evaluated thermal-neutron capture cross-section should give the same value of the thermal-neutron flux component if the cross section is suitable. This time, we found that the cross sections of $$^{45}$$Sc and $$^{94}$$Zn were consistent with the evaluated one, but those of other nuclides were inconsistent with their evaluated ones; that is, it turned out that their thermal-neutron capture cross-sections should be modified.

Journal Articles

Measurement of spent nuclear fuel burn-up using a new H$$(n,gamma)$$ method

Nauchi, Yasushi*; Sato, Shunsuke*; Hayakawa, Takehito*; Kimura, Yasuhiko; Suyama, Kenya; Kashima, Takao*; Futakami, Kazuhiro*

Nuclear Instruments and Methods in Physics Research A, 1050, p.168109_1 - 168109_9, 2023/05

 Times Cited Count:0 Percentile:0.02(Instruments & Instrumentation)

Measurement of neutrons from spent nuclear fuel is performed in this study using the H$$(n,gamma)$$ method, which detects 2.223 MeV $$gamma$$ rays from neutron capture reaction of hydrogen using a highly pure germanium (HPGe) detector. The detection of the 2.223 MeV $$gamma$$ ray is affected by intense $$gamma$$ ray emission from fission products (FPs) because the emission rate of $$gamma$$ rays from the FP is seven orders of magnitude higher than the emission rate of neutrons. To shield the intense $$gamma$$ ray from the FP, the HPGe detector is placed off the axis of a collimator, whereas a polyethylene block is placed on the axis. In this geometry, the detector is shielded from the intense $$gamma$$ rays from the FP, but the detector can measure 2.223 MeV $$gamma$$ rays from the H$$(n,gamma)$$ reactions in the polyethylene block. The measured count rate of the 2.223 MeV $$gamma$$ rays is consistent with the expected rate within the statistical error, which is calculated based on the nuclide composition, which is primary $$^{244}$$Cm, estimated via depletion and decay calculations. Accordingly, the H$$(n,gamma)$$ method is considered feasible to quantify the number of neutron leakage from spent nuclear fuel assembly, which is applicable to certify burn up of the assembly.

Journal Articles

Investigation of radioactive samples for neutron capture reaction measurements using energy-resolved neutron imaging

Segawa, Mariko; Toh, Yosuke; Kai, Tetsuya; Kimura, Atsushi; Nakamura, Shoji

Annals of Nuclear Energy, 167, p.108828_1 - 108828_5, 2022/03

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

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

Neutron capture cross sections of light neutron-rich nuclei relevant for $$r$$-process nucleosynthesis

Bhattacharyya, A.*; Datta, U.*; Rahaman, A.*; Chakraborty, S.*; Aumann, T.*; Beceiro-Novo, S.*; Boretzky, K.*; Caesar, C.*; Carlson, B. V.*; Catford, W. N.*; et al.

Physical Review C, 104(4), p.045801_1 - 045801_14, 2021/10

AA2021-0553.pdf:7.41MB

 Times Cited Count:5 Percentile:57.13(Physics, Nuclear)

no abstracts in English

Journal Articles

Thermal-neutron capture cross-section measurement of $$^{237}$$Np using graphite thermal column

Nakamura, Shoji; Endo, Shunsuke; Kimura, Atsushi; Shibahara, Yuji*

KURNS Progress Report 2020, P. 94, 2021/08

The present study selected $$^{237}$$Np among radioactive nuclides and aimed to converge a contradiction between reported thermal-neutron capture cross sections. Neutron irradiation was carried out using the graphite thermal column equipped with the Kyoto University Research Reactor. A solution equivalent to 950 Bq order of radioactivity was pipetted out of a $$^{237}$$Np standard solution and dropped onto a fiber filter, which was then dried with an infrared lamp to prepare a $$^{237}$$Np sample. The $$^{237}$$Np sample was quantified using 312-keV gamma ray emitted from $$^{233}$$Pa in a radiation equilibrium with $$^{237}$$Np. To monitor a thermal-neutron flux component at an irradiation position, the $$^{237}$$Np sample was irradiated together with several stable nuclides as neutron flux monitors: $$^{45}$$Sc, $$^{59}$$Co, $$^{98}$$Mo, $$^{181}$$Ta and $$^{197}$$Au. The reaction rate of $$^{237}$$Np was obtained from gamma-ray yields given by $$^{238}$$Np and $$^{233}$$Pa, and then the thermal-neutron capture cross section of $$^{237}$$Np was derived.

Journal Articles

Discovery of a new low energy neutron resonance of $$^{89}$$Y

Katabuchi, Tatsuya*; Toh, Yosuke; Mizumoto, Motoharu*; Saito, Tatsuhiro*; Terada, Kazushi*; Kimura, Atsushi; Nakamura, Shoji; Huang, M.*; Rovira Leveroni, G.; Igashira, Masayuki*

European Physical Journal A, 57(1), p.4_1 - 4_4, 2021/01

 Times Cited Count:3 Percentile:46.8(Physics, Nuclear)

Journal Articles

Fast neutron capture reaction data measurement of minor actinides for development of nuclear transmutation systems

Katabuchi, Tatsuya*; Iwamoto, Osamu; Hori, Junichi*; Kimura, Atsushi; Iwamoto, Nobuyuki; Nakamura, Shoji; Shibahara, Yuji*; Terada, Kazushi*; Rovira, G.*; Matsuura, Shota*

EPJ Web of Conferences, 239, p.01044_1 - 01044_4, 2020/09

 Times Cited Count:2 Percentile:86.93(Nuclear Science & Technology)

Journal Articles

Simultaneous determination of neutron-induced fission and radiative capture cross sections from decay probabilities obtained with a surrogate reaction

P$'e$rez S$'a$nchez, R.*; Jurado, B.*; M$'e$ot, V.*; Roig, O.*; Dupuis, M.*; Bouland, O.*; Denis-Petit, D.*; Marini, P.*; Mathieu, L.*; Tsekhanovich, I.*; et al.

Physical Review Letters, 125(12), p.122502_1 - 122502_5, 2020/09

 Times Cited Count:13 Percentile:70.32(Physics, Multidisciplinary)

Journal Articles

Neutron capture reaction data measurement of minor actinides in fast neutron energy region for study on nuclear transmutation system

Katabuchi, Tatsuya*; Iwamoto, Osamu; Hori, Junichi*; Iwamoto, Nobuyuki; Kimura, Atsushi; Nakamura, Shoji; Shibahara, Yuji*; Terada, Kazushi*

JAEA-Conf 2019-001, p.193 - 197, 2019/11

Journal Articles

Measurements of gamma-ray emission probabilities in the decay of americium-244g

Nakamura, Shoji; Terada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Iwamoto, Osamu; Harada, Hideo; Uehara, Akihiro*; Takamiya, Koichi*; Fujii, Toshiyuki*

Journal of Nuclear Science and Technology, 56(1), p.123 - 129, 2019/01

 Times Cited Count:1 Percentile:11.15(Nuclear Science & Technology)

Accurate data of $$gamma$$-ray emission probabilities are frequently needed when one quantitatively determines the amount of isotope by $$gamma$$-ray measurements or obtains neutron capture cross-sections using them. Americium-243, one of the most important minor actinides, produces $$^{244}$$Am after neutron capture. The 744-keV $$gamma$$-ray decaying from the ground state of $$^{244}$$Am has a relatively large $$gamma$$-ray emission probability c.a. 66%, however, its uncertainty is as large as 29%. The uncertainty of the $$gamma$$-ray emission probability leads to a major factor of the systematic uncertainty on determining an amount of isotope, and therefore the $$gamma$$-ray emission probability was measured by using an activation method and an examined level structure of $$^{244}$$Cm. In this study, the emission probability of 744-keV $$gamma$$ ray was derived as 66.5$$pm$$1.1%, and its uncertainty was improved from 29% to 2%.

Journal Articles

Simultaneous measurement of neutron-induced fission and capture cross sections for $$^{241}$$Am at neutron energies below fission threshold

Hirose, Kentaro; Nishio, Katsuhisa; Makii, Hiroyuki; Nishinaka, Ichiro*; Ota, Shuya*; Nagayama, Tatsuro*; Tamura, Nobuyuki*; Goto, Shinichi*; Andreyev, A. N.; Vermeulen, M. J.; et al.

Nuclear Instruments and Methods in Physics Research A, 856, p.133 - 138, 2017/06

 Times Cited Count:5 Percentile:44.54(Instruments & Instrumentation)

Journal Articles

Measurement of the $$^{133}$$Cs(n,$$gamma$$) cross-section using a New DAQ System at ANNRI

Hales, B. P.; Nakamura, Shoji; Kimura, Atsushi; Iwamoto, Osamu

J-PARC 17-07; J-PARC MLF Annual Report 2016, p.88 - 89, 2017/03

Journal Articles

The Measurement of $$^{77}$$Se($$gamma$$, n) cross section and the evaluation of uncertainty of $$^{79}$$Se(n, $$gamma$$) cross section

Kitatani, Fumito

Kaku Deta Nyusu (Internet), (114), p.44 - 49, 2016/06

no abstracts in English

Journal Articles

Search for neutron resonances of $$^{106}$$Pd

Nakamura, Shoji; Kimura, Atsushi; Toh, Yosuke; Harada, Hideo; Katabuchi, Tatsuya*; Mizumoto, Motoharu*; Igashira, Masayuki*; Hori, Junichi*; Kino, Koichi*

JAEA-Conf 2015-003, p.113 - 118, 2016/03

Experiments were carried out with the Ge detector of ANNRI to confirm whether or not the weak resonances were surely due to $$^{106}$$Pd. The prompt $$gamma$$ rays due to capture reaction of $$^{106}$$Pd were clearly observed at the $$gamma$$-ray energy at 115 kev and around 300 keV. When a TOF spectrum was extracted by gating at the prompt $$gamma$$ ray around 300 keV, the small resonance peaks were revealed at the neutron energy of 146 and 156 eV.

Journal Articles

Current activities and future plans for nuclear data measurements at J-PARC

Kimura, Atsushi; Harada, Hideo; Nakamura, Shoji; Iwamoto, Osamu; Toh, Yosuke; Koizumi, Mitsuo; Kitatani, Fumito; Furutaka, Kazuyoshi; Igashira, Masayuki*; Katabuchi, Tatsuya*; et al.

European Physical Journal A, 51(12), p.180_1 - 180_8, 2015/12

 Times Cited Count:3 Percentile:30.26(Physics, Nuclear)

Journal Articles

Neutron capture cross section and capture $$gamma$$-ray spectra of $$^{138}$$Ba in the keV-neutron energy region

Katabuchi, Tatsuya*; Yanagida, Shotaro*; Terada, Kazushi; Iwamoto, Nobuyuki; Igashira, Masayuki*

EPJ Web of Conferences, 93, p.02008_1 - 02008_2, 2015/05

 Times Cited Count:0 Percentile:0.16(Physics, Multidisciplinary)

$$^{138}$$Ba has the smallest neutron capture cross section among the stable Ba isotopes. The neutron capture reaction of $$^{138}$$Ba is dominated by resolved resonances in the astrophysically relevant energy region. Thus, reliable experimental data of the capture cross section are necessary. In the present work, we measured the neutron capture cross section of $$^{138}$$Ba in the energy region from 15 to 100 keV by the time-of-flight method at the Tokyo Institute of Technology. The capture cross sections were obtained from the pulse height spectra by the pulse-height weighting technique. A comparison of the present results with previous experimental data and evaluated data was made. We also derived $$gamma$$-ray spectra by unfolding the pulse height spectra. It was revealed that the shape of $$gamma$$-ray spectra strongly depends on neutron energy.

Journal Articles

Research and development for accuracy improvement of neutron nuclear data on minor actinides

Harada, Hideo

Kaku Deta Nyusu (Internet), (109), p.44 - 47, 2014/10

Improvement of accuracy of neutron nuclear data for minor actinides (MAs) and long-lived fission products (LLFPs) is required for developing innovative nuclear system transmuting these nuclei. In order to meet the requirement, the project entitled as "Research and development for Accuracy Improvement of neutron nuclear data on Minor ACtinides (AIMAC)" has been started as one of the "Innovative Nuclear Research and Development Program". The AIMAC project team is composed of researchers in four different fields: differential nuclear data measurement, integral nuclear data measurement, nuclear chemistry, and nuclear data evaluation. By integrating all of the forefront knowledge and techniques in these fields, the research project team aims at improving the accuracy of the data. The background, goal and brief research plan of the AIMAC project are explained.

Journal Articles

Maxwellian-averaged neutron-induced reaction cross sections and astrophysical reaction rates for $$kT$$ = 1 keV to 1 MeV calculated from microscopic neutron cross section library JENDL-3.3

Nakagawa, Tsuneo; Chiba, Satoshi; Hayakawa, Takehito; Kajino, Toshitaka*

Atomic Data and Nuclear Data Tables, 91(2), p.77 - 186, 2005/11

 Times Cited Count:24 Percentile:79.73(Physics, Atomic, Molecular & Chemical)

no abstracts in English

86 (Records 1-20 displayed on this page)