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Journal Articles

Measurement of thick target neutron yield at 180$$^{circ}$$ for a mercury target induced by 3-GeV protons

Matsuda, Hiroki; Iwamoto, Hiroki; Meigo, Shinichiro; Takeshita, Hayato*; Maekawa, Fujio

Nuclear Instruments and Methods in Physics Research B, 483, p.33 - 40, 2020/11

A thick target neutron yield for a mercury target at an angle of 180$$^{circ}$$ from the incident beam direction is measured with the time-of-flight method using a 3-GeV proton beam at the Japan Proton Accelerator Research Complex (J-PARC). Comparing the experimental result with a Monte Carlo particle transport simulation by the Particle and Heavy Ion Transport code System (PHITS) shows that there are apparent discrepancies. We find that this trend is consistent with an experimental result of neutron-induced re- action rates obtained using indium and niobium activation foils. Comparing proton-induced neutron-production double-differential cross-sections for a lead target at backward directions between the PHITS calculation and experimental data suggests that the dis- crepancies for our experiments would be linked to the neutron production calculation around 3 GeV by the PHITS spallation model and/or the calculation of nonelastic cross-sections around 3 GeV in the particle transport simulation.

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

Measurements of thermal-neutron capture cross-section of cesium-135 by applying mass spectrometry

Nakamura, Shoji; Shibahara, Yuji*; Kimura, Atsushi; Iwamoto, Osamu; Uehara, Akihiro*; Fujii, Toshiyuki*

Journal of Nuclear Science and Technology, 57(4), p.388 - 400, 2020/04

 Times Cited Count:1 Percentile:56.06(Nuclear Science & Technology)

The thermal-neutron capture cross-section ($$sigma_{0}$$) and resonance integral(I$$_{0}$$) were measured for the $$^{135}$$Cs(n,$$gamma$$)$$^{136}$$Cs reaction by an activation method and mass spectrometry. We used $$^{135}$$Cs contained as an impurity in a normally available $$^{137}$$Cs standard solution. An isotope ratio of $$^{135}$$Cs and $$^{137}$$Cs in a standard $$^{137}$$Cs solution was measured by mass spectrometry to quantify $$^{135}$$Cs. The analyzed $$^{137}$$Cs samples were irradiated at the hydraulic conveyer of the research reactor in Institute for Integral Radiation and Nuclear Science, Kyoto University. Wires of Co/Al and Au/Al alloys were used as neutron monitors to measure thermal-neutron fluxes and epi-thermal Westcott's indices at an irradiation position. A gadolinium filter was used to measure the $$sigma_{0}$$, and a value of 0.133 eV was taken as the cut-off energy. Gamma-ray spectroscopy was used to measure induced activities of $$^{137}$$Cs, $$^{136}$$Cs and monitor wires. On the basis of Westcott's convention, the $$sigma_{0}$$ and I$$_{0}$$ values were derived as 8.57$$pm$$0.25 barn, and 45.3$$pm$$3.2 barn, respectively. The $$sigma_{0}$$ obtained in the present study agreed within the limits of uncertainties with the past reported value of 8.3$$pm$$0.3 barn.

Journal Articles

Activation measurement for thermal-neutron capture cross-section of Cesium-135

Nakamura, Shoji; Kimura, Atsushi; Iwamoto, Osamu; Shibahara, Yuji*; Uehara, Akihiro*; Fujii, Toshiyuki*

KURNS Progress Report 2018, P. 106, 2019/08

Under the ImPACT project, the neutron capture cross-section measurements of Cesium-135 ($$^{135}$$Cs) among the long-lived fission products have been performed at Kyoto University. This paper reports measurements of the thermal-neutron capture cross-section of $$^{135}$$Cs at the Kyoto University Research Reactor (KUR).

Journal Articles

Measurements of thermal-neutron capture cross-section and resonance integral of neptunium-237

Nakamura, Shoji; Kitatani, Fumito; Kimura, Atsushi; Uehara, Akihiro*; Fujii, Toshiyuki*

Journal of Nuclear Science and Technology, 56(6), p.493 - 502, 2019/06

 Times Cited Count:2 Percentile:31.52(Nuclear Science & Technology)

The thermal-neutron capture cross-section($$sigma_{0}$$)and resonance integral(I$$_{0}$$) were measured for the $$^{237}$$Np(n,$$gamma$$)$$^{238}$$Np reaction by an activation method. A method with a Gadolinium filter, which is similar to the Cadmium difference method, was used to measure the $$sigma_{0}$$ with paying attention to the first resonance at 0.489 eV of $$^{237}$$Np, and a value of 0.133 eV was taken as a cut-off energy. Neptunium-237 samples were irradiated at the pneumatic tube of the Kyoto University Research Reactor in Institute for Integral Radiation and Nuclear Science, Kyoto University. Wires of Co/Al and Au/Al alloys were used as monitors to determine thermal-neutron fluxes and epi-thermal Westcott's indices at an irradiation position. A $$gamma$$-ray spectroscopy was used to measure activities of $$^{237}$$Np, $$^{238}$$Np and neutron monitors. On the basis of Westcott's convention, the $$sigma_{0}$$ and I$$_{0}$$ values were derived as 186.9$$pm$$6.2 barn, and 1009$$pm$$90 barn, respectively.

Journal Articles

Measurements and analyses of the distribution of the radioactivity induced by the secondary neutrons produced by 17-MeV protons in compact cyclotron facility

Matsuda, Norihiro; Izumi, Yuichi*; Yamanaka, Yoshiyuki*; Gando, Toshiyuki*; Yamada, Masaaki*; Oishi, Koji*

EPJ Web of Conferences, 153, p.07001_1 - 07001_6, 2017/09

 Times Cited Count:0 Percentile:100

Journal Articles

R&D of active neutron NDA techniques for nuclear nonproliferation and nuclear security, 3; Validation of neutron transport code for design of NDA system

Maeda, Makoto; Komeda, Masao; Tobita, Hiroshi; Ozu, Akira; Kureta, Masatoshi; Bogucarska, T.*; Crochemore, J. M.*; Varasano, G.*; Pedersen, B.*

Dai-37-Kai Kaku Busshitsu Kanri Gakkai Nippon Shibu Nenji Taikai Rombunshu (CD-ROM), 7 Pages, 2017/02

JAEA and EC/JRC are carrying out collaborative research to develop NDA techniques that can be utilized for quantification of high radioactive special nuclear materials such as spent fuel and next generation minor actinide fuels. In the research, reliability of neutron transport codes is important because it is utilized for design and development of a demonstration system of next-generation Differential Die-away (DDA) technique in JAEA. In order to evaluate the reliability, actual neutron flux distribution in a sample cavity was examined in PUNITA device using JRC type DDA technique and JAWAS-T device using JAEA type DDA technique, and then the measurement results were compared with the simulation results obtained by the neutron transport codes. The neutron flux distribution in the target matrix was also examined in the PUNITA and compared with the simulation results. We report on the measurement and simulation results of the neutron flux distribution and evaluation results of the reliability of the neutron transport codes.

Journal Articles

Activation measurements of neputunium-237 at KURRI-Linac

Nakamura, Shoji; Terada, Kazushi; Shibahara, Yuji*; Uehara, Akihiro*; Fujii, Toshiyuki*; Sano, Tadafumi*; Takahashi, Yoshiyuki*; Hori, Junichi*

KURRI Progress Report 2015, P. 67, 2016/08

The activation measurements of Np-237 were performed with neutron sources at KURRI-Linac. It was found that activation measurements supported the evaluated cross-section data of JENDL-4.0.

Journal Articles

Measurements of americium isotopes by activation method at KURRI-Linac

Nakamura, Shoji; Terada, Kazushi; Takahashi, Yoshiyuki*; Sano, Tadafumi*; Hori, Junichi*

KURRI Progress Report 2015, P. 69, 2016/08

Neutron capture cross section measurements has been conducted for Minor Actinides (MAs) under the research project entitled by "Research and development for Accuracy Improvement of neutron nuclear data on Minor ACtinides (AIMAC)". The present work selected two americium isotopes, $$^{241}$$Am and $$^{243}$$Am, were selected, and measurements were carried out by an activation method with neutron sources at KURRI-Linac. It was found that the neutron flux at the target positon was of the order of 10$$^{8}$$ (n/cm$$^{2}$$s). The reaction rates of $$^{241}$$Am and $$^{243}$$Am were obtained by $$alpha$$- and $$gamma$$-ray measurements of the irradiated Am samples.

Journal Articles

Evaluation of neutron flux distribution in the JAEA type and JRC type DDA systems

Maeda, Makoto; Komeda, Masao; Tobita, Hiroshi; Ozu, Akira; Kureta, Masatoshi; Bogucarska, T.*; Crochemore, J. M.*; Varasano, G.*; Pedersen, B.*

Proceedings of INMM 57th Annual Meeting (Internet), 9 Pages, 2016/07

The JAEA and EC/JRC have started collaborative research to develop a technique that can be utilized for quantification of high radioactive special nuclear materials such as next generation minor actinide fuels. In the study of a Differential Die-Away (DDA) technique, which is one of the techniques to be improved in the collaborative research, JRC type and JAEA type DDA techniques are compared. In the JRC type DDA technique, large amount of thermal neutron is generated using D-T neutron generator and graphite moderator to accomplish high detection sensitivity for small amount of fissile material. On the other hand, in JAEA type, relatively hard neutron spectrum and moderation of neutron in the target matrix are utilized to minimize position dependence of detection efficiency. Estimation of the neutron field is important to evaluate the performance of the system in DDA technique. The purpose of this study is to validate simulation results by experimental results and evaluate neutron flux distribution in the system by the simulation and the experiment. In this paper, we present the evaluation results of the neutron flux distributions in PUNITA which utilizes JRC type DDA technique and JAWAS-T which utilizes JAEA type DDA technique obtained by Monte Carlo simulation and activation method.

JAEA Reports

Measurement of high-energy neutron fluxes and spectra around the J-PARC mercury spallation neutron target using multi-foil activation method

Kasugai, Yoshimi; Harada, Masahide; Kai, Tetsuya; Oi, Motoki; Meigo, Shinichiro; Maekawa, Fujio

JAEA-Data/Code 2015-033, 28 Pages, 2016/03

JAEA-Data-Code-2015-033.pdf:1.78MB

The high-energy neutron fluxes and spectra around the mercury spallation neutron source at MLF of J-PARC were measured by the multi-foil activation method. The threshold energies of neutron reactions utilized in this experiment covered from 0.1 to 50 MeV. The foil irradiation was carried out on the first beam-run of MLF from May 30th to 31th, 2008. After the irradiation, the induced radioactivity of each foil was measured using an HPGe detector, and the neutron-induced reaction-rate distribution around the mercury target was determined. Using these data, the high-energy neutron fluxes and spectra were deduced with unfolding method in which the neutron spectra calculated with PHITS code were used as the initial-guess spectra. By comparison between the initial and the unfolded spectra, it was shown that most of the calculation results, which had been the basis of the neutronics design of the MLF target assembly, were consistent with the experimental data within $$pm$$30%.

Journal Articles

Methods for tritium production rate measurement in design-oriented blanket experiments

Verzilov, Y. M.; Ochiai, Kentaro; Nishitani, Takeo

Fusion Science and Technology, 48(1), p.650 - 653, 2005/07

 Times Cited Count:7 Percentile:51.34(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Measurements of deuteron-induced activation cross sections for IFMIF accelerator structural materials

Nakao, Makoto*; Hori, Junichi*; Ochiai, Kentaro; Sato, Satoshi; Yamauchi, Michinori*; Ishioka, Noriko; Nishitani, Takeo

Proceedings of International Conference on Nuclear Data for Science and Technology (ND 2004), p.1489 - 1492, 2004/09

no abstracts in English

Journal Articles

In-phantom two-dimensinal thermal neutron distribution for intraoperative boron neutron capture therapy of brain tumours

Yamamoto, Tetsuya*; Matsumura, Akira*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Shibata, Yasushi*; Nose, Tadao*

Physics in Medicine & Biology, 47(14), p.2387 - 2396, 2002/07

 Times Cited Count:17 Percentile:52.48(Engineering, Biomedical)

The aim of this study was to determine the in-phantom thermal distribution derived from neutron beams for intraoperative boron neutron capture therapy (IOBNCT). Gold activation wires arranged in a cylindrical water phantom with (void-in phantom) or without (standard phantom) a cylinder styrene form placed inside were irradiated by using the epithermal beam (ENB) and the mixed thermal-epithermal beam (TNB-1) at the JRR-4. The thermal neutron distribution derived from both the ENB and TNB-1 was significantly improved in the void-in-phantom, and a double high dose area was formed lateral to the void. The flattened distribution in the circumference of the void was observed with the combination of ENB and the void-in-phantom. The measurement data suggest that the ENB may provide a clinical advantage in the form of an enhanced and flattened dose delivery to the marginal tissue in which residual and/or microscopically infiltrating tumor.

Journal Articles

Measurements of neutron spallation cross sections of $$^{12}$$C and $$^{209}$$Bi in the 20- to 150-MeV energy range

E.Kim*; Nakamura, Takashi*; *; Uwamino, Y.*; *; Imamura, Mineo*; Nakao, Noriaki*; *;

Nuclear Science and Engineering, 129(3), p.209 - 223, 1998/00

 Times Cited Count:62 Percentile:2.62(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Characteristics of a deuterium-tritium fusion source on a rotating target used in simulated fusion blanket experiments

Nakakawa, Masayuki; Mori, Takamasa; Kosako, Kazuaki*; Oyama, Yukio; Ikeda, Yujiro; Konno, Chikara; Maekawa, Hiroshi; *; M.A.Abdou*; Bennett, E. F.*; et al.

Fusion Technology, 28, p.39 - 55, 1995/08

no abstracts in English

Journal Articles

Measurement of the thermal neutron cross section of the $$^{90}$$Sr(n,$$gamma$$)$$^{91}$$Sr reaction

Harada, Hideo*; Sekine, Toshiaki; ; ; Kobayashi, Katsutoshi; Otsuki, Tsutomu*; Kato, Toshio*

Journal of Nuclear Science and Technology, 31(3), p.173 - 179, 1994/03

 Times Cited Count:23 Percentile:13.05(Nuclear Science & Technology)

no abstracts in English

JAEA Reports

Journal Articles

Journal Articles

Neutron dosimetry

Ikezoe, Yasumasa

Hoshasen Kagaku, 19(38), p.45 - 47, 1984/00

no abstracts in English

22 (Records 1-20 displayed on this page)