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Journal Articles

Effect of sample density in prompt $$gamma$$-ray analysis

Maeda, Makoto; Segawa, Mariko; Toh, Yosuke; Endo, Shunsuke; Nakamura, Shoji; Kimura, Atsushi

Scientific Reports (Internet), 12(1), p.6287_1 - 6287_8, 2022/06

Journal Articles

KeV-neutron capture cross-section measurement of $$^{197}$$Au with a Cr-filtered neutron beam at the ANNRI beamline of MLF/J-PARC

Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Kodama, Yu*; Nakano, Hideto*; Sato, Yaoki*; et al.

Journal of Nuclear Science and Technology, 59(5), p.647 - 655, 2022/05

Journal Articles

Thermal-neutron capture cross-section measurements of neptunium-237 with graphite thermal column in KUR

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

Journal of Nuclear Science and Technology, 11 Pages, 2022/04

The present study selected $$^{237}$$Np among radioactive nuclides and aimed to measure the thermal-neutron capture cross-section for $$^{237}$$Np in a well-thermalized neutron field by an activation method. A $$^{237}$$Np standard solution was used for irradiation samples. A thermal-neutron flux at an irradiation position was measured with neutron flux monitors: $$^{45}$$Sc, $$^{59}$$Co, $$^{98}$$Mo, $$^{181}$$Ta and $$^{197}$$Au. The $$^{237}$$Np sample and flux monitors were irradiated together for 30 minutes in the graphite thermal column equipped with the Kyoto University Research Reactor. The similar irradiation was carried out twice. After the irradiations, the $$^{237}$$Np samples were quantified using 312-keV gamma ray emitted from $$^{233}$$Pa in a radiation equilibrium with $$^{237}$$Np. The reaction rates of $$^{237}$$Np were obtained from gamma-ray peak net counts given by $$^{238}$$Np, and then the thermal-neutron capture cross-section of $$^{237}$$Np was found to be 173.8$$pm$$4.4 barn by averaging the results obtained by the two irradiations. The present result was in agreement with the reported data given by a time-of-flight method within the limit of uncertainty.

Journal Articles

Neutron capture and total cross-section measurements and resonance parameter analysis of niobium-93 below 400 eV

Endo, Shunsuke; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Iwamoto, Nobuyuki; Rovira Leveroni, G.; Terada, Kazushi*; Meigo, Shinichiro; Toh, Yosuke; Segawa, Mariko; et al.

Journal of Nuclear Science and Technology, 59(3), p.318 - 333, 2022/03

Journal Articles

Measurements of the neutron capture cross section of $$^{243}$$Am around 23.5 keV

Kodama, Yu*; Katabuchi, Tatsuya*; Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Nobuyuki; Iwamoto, Osamu; Hori, Junichi*; Shibahara, Yuji*; et al.

Journal of Nuclear Science and Technology, 58(11), p.1159 - 1164, 2021/11

Journal Articles

Thermal-neutron capture cross-section measurement of tantalum-181 using graphite thermal column at KUR

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

Journal of Nuclear Science and Technology, 58(10), p.1061 - 1070, 2021/10

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

In a well-thermalized neutron field, it is principally possible to drive a thermal-neutron capture cross-section without considering an epithermal neutron component. This was demonstrated by a neutron activation method using the graphite thermal column (TC-Pn) of the Kyoto University Research Reactor. First, in order to confirm that the graphite thermal column was a well-thermalized neutron field, neutron irradiation was performed with neutron flux monitors: $$^{197}$$Au, $$^{59}$$Co, $$^{45}$$Sc, $$^{63}$$Cu, and $$^{98}$$Mo. The TC-Pn was confirmed to be extremely thermalized on the basis of Westcott's convention, because the thermal-neutron flux component took a constant value regardless of the sensitivity of each flux monitor to epithermal neutrons. Next, as a demonstration, the thermal-neutron capture cross section of $$^{181}$$Ta(n,$$gamma$$)$$^{182m+g}$$Ta reaction was measured using the graphite thermal column, and then derived to be 20.5$$pm$$0.4 barn, which supported the evaluated value of 20.4$$pm$$0.3 barn. The $$^{181}$$Ta nuclide could be useful as a flux monitor that complements the sensitivity between $$^{197}$$Au and $$^{98}$$Mo monitors.

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

Nondestructive quantitative analysis of difficult-to-measure radionuclides $$^{107}$$Pd and $$^{99}$$Tc

Toh, Yosuke; Segawa, Mariko; Maeda, Makoto; Tsuneyama, Masayuki*; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Ebihara, Mitsuru*

Analytical Chemistry, 93(28), p.9771 - 9777, 2021/07

Journal Articles

Neutron beam filter system for fast neutron cross-section measurement at the ANNRI beamline of MLF/J-PARC

Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Terada, Kazushi*; Kodama, Yu*; Nakano, Hideto*; et al.

Nuclear Instruments and Methods in Physics Research A, 1003, p.165318_1 - 165318_10, 2021/07

 Times Cited Count:0 Percentile:0.03(Instruments & Instrumentation)

Journal Articles

Energy-dependent angular distribution of individual $$gamma$$ rays in the $$^{139}$$La($$n, gamma$$)$$^{140}$$La$$^{ast}$$ reaction

Okudaira, Takuya*; Endo, Shunsuke; Fujioka, Hiroyuki*; Hirota, Katsuya*; Ishizaki, Kohei*; Kimura, Atsushi; Kitaguchi, Masaaki*; Koga, Jun*; Ninomi, Yudai*; Sakai, Kenji; et al.

Physical Review C, 104(1), p.014601_1 - 014601_6, 2021/07

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

Journal Articles

Thermal-neutron capture cross sections and resonance integrals of the $$^{243}$$Am(n,$$gamma$$)$$^{rm 244g}$$Am and $$^{243}$$Am(n,$$gamma$$)$$^{rm 244m+g}$$Am reactions

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

Journal of Nuclear Science and Technology, 58(3), p.259 - 277, 2021/03

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

Research and development were made for accuracy improvement of neutron capture cross section data on $$^{243}$$Am among minor actinides. First, the emission probabilities of decay $$gamma$$ rays were obtained with high accuracy, and the amount of the ground state of $$^{244}$$Am produced by reactor neutron irradiation of $$^{243}$$Am was examined by $$gamma$$-ray measurement. Next, the total amount of isomer and ground states was examined by $$alpha$$-ray measurement. Thermal-neutron capture cross sections and resonance integrals were derived both for the $$^{243}$$Am(n,$$gamma$$)$$^{rm 244g}$$Am and for $$^{243}$$Am(n,$$gamma$$)$$^{rm 244m+g}$$Am reactions.

Journal Articles

Development and application of a $$^3$$He neutron spin filter at J-PARC

Okudaira, Takuya; Oku, Takayuki; Ino, Takashi*; Hayashida, Hirotoshi*; Kira, Hiroshi*; Sakai, Kenji; Hiroi, Kosuke; Takahashi, Shingo*; Aizawa, Kazuya; Endo, Hitoshi*; et al.

Nuclear Instruments and Methods in Physics Research A, 977, p.164301_1 - 164301_8, 2020/10

 Times Cited Count:4 Percentile:76.41(Instruments & Instrumentation)

Journal Articles

Measurement for thermal neutron capture cross sections and resonance integrals of the $$^{243}$$Am(n,$$gamma$$)$$^{rm 244g}$$Am, $$^{rm 244m+g}$$Am reactions

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

KURNS Progress Report 2019, P. 132, 2020/08

Research and development were made for accuracy improvement of neutron capture cross section data on $$^{243}$$Am among minor actinides. First, the emission probabilities of decay $$gamma$$ rays were obtained with high accuracy, and the amount of the ground state of $$^{244}$$Am produced by reactor neutron irradiation of $$^{243}$$Am was examinded by $$gamma$$-ray measurement. Next, the total amount of isomer and ground states was examoned by $$alpha$$-ray measurement.

Journal Articles

Measurement of the angular distribution of $$gamma$$-rays after neutron capture by $$^{139}$$La for a T-violation search

Okudaira, Takuya; Shimizu, Hirohiko*; Kitaguchi, Masaaki*; Hirota, Katsuya*; Haddock, C. C.*; Ito, Ikuya*; Yamamoto, Tomoki*; Endo, Shunsuke*; Ishizaki, Kohei*; Sato, Takumi*; et al.

EPJ Web of Conferences, 219, p.09001_1 - 09001_6, 2019/12

Parity violating effects enhanced by up to 10$$^6$$ times have been observed in several neutron induced compound nuclei. There is a theoretical prediction that time reversal (T) violating effects can also be enhanced in these nuclei implying that T-violation can be searched for by making very sensitive measurements. However, the enhancement factor has not yet been measured in all nuclei. The angular distribution of the (n,$$gamma$$) reaction was measured with $$^{139}$$La by using a germanium detector assembly at J-PARC, and the enhancement factor was obtained. From the result, the measurement time to achieve the most sensitive T-violation search was estimated as 1.4 days, and a 40% polarized $$^{139}$$La target and a 70% polarized $$^3$$He spin filter whose thickness is 70 atm$$cdot$$cm are needed. Therefore high quality $$^3$$He spin filter is developed in JAEA. The measurement result of the (n,$$gamma$$) reaction at J-PARC and the development status of the $$^3$$He spin filter will be presented.

Journal Articles

Field test around Fukushima Daiichi Nuclear Power Plant site using improved Ce:Gd$$_{3}$$(Al,Ga)$$_{5}$$O$$_{12}$$ scintillator Compton camera mounted on an unmanned helicopter

Shikaze, Yoshiaki; Nishizawa, Yukiyasu; Sanada, Yukihisa; Torii, Tatsuo; Jiang, J.*; Shimazoe, Kenji*; Takahashi, Hiroyuki*; Yoshino, Masao*; Ito, Shigeki*; Endo, Takanori*; et al.

Journal of Nuclear Science and Technology, 53(12), p.1907 - 1918, 2016/12

 Times Cited Count:24 Percentile:96.18(Nuclear Science & Technology)

The Compton camera was improved for use with the unmanned helicopter. Increase of the scintillator array from 4$$times$$4 to 8$$times$$8 and expanse of the distance between the two layers contributed to the improvements of detection efficiency and angular resolution, respectively. Measurements were performed over the riverbed of the Ukedo river of Namie town in Fukushima Prefecture. By programming of flight path and speed, the areas of 65 m $$times$$ 60 m and 65 m $$times$$ 180 m were measured during about 20 and 30 minutes, respectively. By the analysis the air dose rate maps at 1 m height were obtained precisely with the angular resolution corresponding to the position resolution of about 10 m from 10 m height. Hovering flights were executed over the hot spot areas for 10-20 minutes at 5-20 m height. By using the reconstruction software the $$gamma$$-ray images including the hot spots were obtained with the angular resolution same as that evaluated in the laboratory (about 10$$^{circ}$$).

Oral presentation

Development of energy recognizable type gamma camera mounted on the unmanned helicopter, 3; Field test around the Fukushima Daiichi NPP site

Shikaze, Yoshiaki; Torii, Tatsuo; Shimazoe, Kenji*; Jiang, J.*; Takahashi, Hiroyuki*; Kurosawa, Shunsuke*; Kamada, Kei*; Yoshikawa, Akira*; Yoshino, Masao*; Ito, Shigeki*; et al.

no journal, , 

no abstracts in English

Oral presentation

Development of energy recognizable type gamma camera mounted on the unmanned helicopter II, 2; Field test around the Fukushima Daiichi NPP site

Shikaze, Yoshiaki; Torii, Tatsuo; Nishizawa, Yukiyasu; Yoshida, Mami*; Shimazoe, Kenji*; Jiang, J.*; Takahashi, Hiroyuki*; Kurosawa, Shunsuke*; Kamada, Kei*; Yoshikawa, Akira*; et al.

no journal, , 

no abstracts in English

Oral presentation

Measurement of total neutron cross section of Niobium-93 at J-PARC MLF ANNRI

Endo, Shunsuke; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Iwamoto, Nobuyuki; Toh, Yosuke; Segawa, Mariko; Maeda, Makoto; Tsuneyama, Masayuki*

no journal, , 

Niobium (Nb)-93, which is mono isotope, is one of the material elements to strengthen stainless steel and is used for structural materials of nuclear reactors. Since Nb is also used as an element of superconductor alloys, it has been used in fields such as fusion reactor and accelerator development. Determination of neutron total cross section with high accuracy is therefore required in the field of nuclear technology. The cross sections of Nb were measured by T. Wang (2011), N. J. Drindak (2006) and so on. However, the resonance parameters determined by them have discrepancies up to about 10% each other. In order to determine the more precise values of resonance parameters, transmission measurements were performed to evaluate total cross section of Nb-93 at the ANNRI of MLF in J-PARC in June of 2019. The ANNRI is one of beamlines in MLF, and Germanium gamma-ray detectors and the Liglass neutron detectors are installed to measure nuclear reactions. A target was natural Nb plate of 25 mm $$times$$ 25 mm $$times$$ 10 mm$$^t$$ whose size was determined from necessary statistic. Since the target size was big and the thermal-neutron capture cross-section is small (about 1.1 barns), the effect of neutron diffraction was observed in low neutron energy region. When discussing reactions to a single nucleus, the effect of diffraction resulting from crystal structure is unnecessary information. Thus, this effect must be estimated and removed to determine the total cross section as nuclear data for a single nucleus. In this poster, I will present preliminary results of the experiment and the estimated effects of neutron diffraction. This work has been supported in part by Grants-in-Aid for Scientific Research (JP17H01076).

Oral presentation

Research and development for accuracy improvement of neutron capture cross-section data on $$^{243}$$Am

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

no journal, , 

Research and development were made for accuracy improvement of neutron capture cross-section data on $$^{243}$$Am among minor actinides. First, the emission probabilities of decay $$gamma$$-rays were obtained with high accuracy, and the amount of the ground state of $$^{244}$$Am produced by reactor neutron irradiation of $$^{243}$$Am was examinded by$$gamma$$-ray measurement. Next, the total amount of isomer and ground states was examoned by $$alpha$$-ray measurement. This presentation will give the details of the measurenmets and the results of the neutron capture cross-sections of $$^{243}$$Am.

Oral presentation

Measurements of neutron total cross section of Nb-93 at J-PARC MLF ANNRI and Estimation of neutron diffraction

Endo, Shunsuke; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Iwamoto, Nobuyuki; Toh, Yosuke; Segawa, Mariko; Maeda, Makoto; Tsuneyama, Masayuki*

no journal, , 

no abstracts in English

44 (Records 1-20 displayed on this page)