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Journal Articles

Characterization of the PTW 34031 ionization chamber (PMI) at RCNP with high energy neutrons ranging from 100 - 392 MeV

Theis, C.*; Carbonez, P.*; Feldbaumer, E.*; Forkel-Wirth, D.*; Jaegerhofer, L.*; Pangallo, M.*; Perrin, D.*; Urscheler, C.*; Roesler, S.*; Vincke, H.*; et al.

EPJ Web of Conferences, 153, p.08018_1 - 08018_5, 2017/09

 Times Cited Count:0 Percentile:0.03

At CERN, gas-filled ionization chambers PTW-34031 (PMI) are commonly used in radiation fields including neutrons, protons and $$gamma$$-rays. A response function for each particle is calculated by the radiation transport code FLUKA. To validate a response function to high energy neutrons, benchmark experiments with quasi mono-energetic neutrons have been carried out at RCNP, Osaka University. For neutron irradiation with energies below 200 MeV, very good agreement was found comparing the FLUKA simulations and the measurements. In addition it was found that at proton energies of 250 and 392 MeV, results calculated with neutron sources underestimate the experimental data due to a non-negligible gamma component originating from the target $$^{7}$$Li(p,n)Be reaction.

Journal Articles

Development of new type passive autocatalytic recombiner, 1; Characterization of monolithic catalyst

Kamiji, Yu; Taniguchi, Masashi*; Nishihata, Yasuo; Nagaishi, Ryuji; Tanaka, Hirohisa*; Hirata, Shingo*; Hara, Mikiya; Hino, Ryutaro

E-Journal of Advanced Maintenance (Internet), 7(1), p.84 - 89, 2015/05

For hydrogen mitigation, a new type passive autocatalytic recombiner is under developing. This new recombiner has been developed from automotive monolithic catalyst in order to reduce weight and to improve hydrogen treating capacity, environmental resistance and product quality. In this study, activation energy of hydrogen-oxygen recombination reaction was examined to clarify the basic characteristics of the catalyst. In addition, the degradation of the catalyst by $$gamma$$-ray irradiation simulating the environmental condition in nuclear power plants was also examined. As a result, the activation energy was experimentally estimated at 5.75 kJ/mol. Besides, no significant differences were observed in compositional distribution from the EPMA results. On the other hand, specific surface area of the catalyst and surface area of the precious metals were increased. Moreover, catalyst performance test showed that $$gamma$$-ray irradiation up to 1.0 MGy can increase activity of catalyst.

Journal Articles

Development of new type passive autocatalytic recombiner, 1; Experimental study on degradation of catalyst

Kamiji, Yu; Matsumura, Daiju; Taniguchi, Masashi*; Nishihata, Yasuo; Tanaka, Hirohisa*; Hirata, Shingo*; Hara, Mikiya; Hino, Ryutaro

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 4 Pages, 2015/05

In a severe accident at a nuclear power plant, a large amount of hydrogen can be released to primary containment vessel or reactor building. Passive autocatalytic recombiner (PAR) is one of the most effective systems for hydrogen mitigation and safety accident management. The new type PAR is under developing to improve conventional PARs, especially its size and weight. In this study, the influence of steam coexistence for the automotive catalyst activity was experimentally examined. These results show that the steam slightly affects the reaction start up and catalyst activity.

Journal Articles

Development of new type passive autocatalytic recombiner, 1; Characterization of monolithic catalyst

Kamiji, Yu; Taniguchi, Masashi*; Nishihata, Yasuo; Nagaishi, Ryuji; Tanaka, Hirohisa*; Hirata, Shingo*; Hara, Mikiya; Hino, Ryutaro

Proceedings of 2nd International Conference on Maintenance Science and Technology (ICMST-Kobe 2014), p.87 - 88, 2014/11

For hydrogen mitigation, a new type passive autocatalytic recombiner is under development. In this study, the activation energy of hydrogen-oxygen recombination reaction was examined to clarify the basic characteristics of the catalyst. In addition, the degradation of the catalyst by $$gamma$$-ray irradiation simulating the environmental condition in nuclear power plants was also examined. As a result, the activation energy was experimentally estimated at 5.75 kJ/mol. Besides, no significant differences were observed in the compositional distribution from the EPMA results between the non-irradiated and the irradiated catalyst. However, the irradiated catalyst showed much more activity because of larger specific surface area of the catalyst and surface area of the precious metals. It showed that $$gamma$$-ray irradiation up to 1.0 MGy can increase activity of the catalyst.

Journal Articles

Thick target neutron yield at 0 degree by 250 and 350 MeV protons

Iwamoto, Yosuke; Taniguchi, Shingo*; Nakao, Noriaki*; Itoga, Toshio*; Nakamura, Takashi*; Nakane, Yoshihiro; Nakashima, Hiroshi; Satoh, Daiki; Yashima, Hiroshi*; Yamakawa, Hiroshi*; et al.

Proceedings of 8th Specialists' Meeting on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-8), p.195 - 203, 2010/03

Neutron energy spectra at 0 degree produced from stopping-length thick graphite, aluminum, iron and lead targets bombarded by 250 MeV and 350 MeV protons were measured at the neutron TOF course at RCNP of Osaka University. The neutron energy spectra were obtained by using the time-of-flight technique in the energy range from 10 MeV to incident proton energy. To compare the experimental results, Monte Carlo calculations by the PHITS and MCNPX codes using the JENDL-HE and the LA150 evaluated nuclear data files were performed. It was found that these calculated results at 0-degree generally underestimated the experimental results for all targets in the energy range above 20 MeV.

Journal Articles

Measurement of thick target neutron yields at 0$$^{circ}$$ bombarded with 140, 250 and 350 MeV protons

Iwamoto, Yosuke; Taniguchi, Shingo*; Nakao, Noriaki*; Itoga, Toshio*; Yashima, Hiroshi*; Nakamura, Takashi*; Satoh, Daiki; Nakane, Yoshihiro; Nakashima, Hiroshi; Kirihara, Yoichi*; et al.

Nuclear Instruments and Methods in Physics Research A, 593(3), p.298 - 306, 2008/08

 Times Cited Count:12 Percentile:61.82(Instruments & Instrumentation)

Neutron energy spectra at 0$$^{circ}$$ produced from stopping-length graphite, aluminum, iron and lead targets bombarded with 140, 250 and 350 MeV protons were measured at the neutron TOF course in RCNP of Osaka University. The neutron energy spectra were obtained by using the time-of-flight technique in the energy range from 10 MeV to incident proton energy. To compare the experimental results, Monte Carlo calculations with the PHITS and MCNPX codes were performed using the JENDL-HE and the LA150 evaluated nuclear data files, the ISOBAR model implemented in PHITS, and the LAHET code in MCNPX. It was found that these calculated results at 0$$^{circ}$$ generally agreed with the experimental results in the energy range above 20 MeV except for graphite at 250 and 350 MeV.

Journal Articles

Development of a quasi-monoenergetic neutron field using the $$^{7}$$Li(p,n)$$^{7}$$Be reaction in the energy range from 250 to 390 MeV at RCNP

Taniguchi, Shingo*; Nakao, Noriaki*; Nakamura, Takashi*; Yashima, Hiroshi*; Iwamoto, Yosuke; Satoh, Daiki; Nakane, Yoshihiro; Nakashima, Hiroshi; Itoga, Toshio*; Tamii, Atsushi*; et al.

Radiation Protection Dosimetry, 126(1-4), p.23 - 27, 2007/08

 Times Cited Count:13 Percentile:66.25(Environmental Sciences)

A quasi-monoenergetic neutron field was developed using the reaction in the energy range from 250 to 390 MeV in the ring cyclotron facility at the Research Center for Nuclear Physics (RCNP), Osaka University. Neutrons were generated from a 10-mm thick Li target injected by 250, 350 and 392 MeV protons. The neutrons produced at 0 degree were extracted into the 100-m long TOF room through a 150-cm thick ironcollimator of 10 cm $$times$$ 12 cm aperture, and were measured by a 12.7-cm diam. $$times$$ 12.7-cm long NE213 organic liquid scintillator. This neutron field is very useful since experimental data for high energy neutrons in this energy region are very scarce. It has already been used for a neutron shielding experiment.

Journal Articles

Measurement of neutron production spectra at the forward direction from thick graphite, aluminum, iron and lead targets bombarded by 250 MeV protons

Iwamoto, Yosuke; Taniguchi, Shingo*; Nakao, Noriaki*; Itoga, Toshio*; Nakamura, Takashi*; Nakane, Yoshihiro; Nakashima, Hiroshi; Satoh, Daiki; Yashima, Hiroshi*; Yamakawa, Hiroshi*; et al.

JAEA-Conf 2006-009, p.118 - 123, 2006/11

Neutron energy spectra produced at the forward direction from thick graphite, aluminum, iron and lead targets bombarded by 250 MeV protons were measured by the TOF method at RCNP of Osaka University. The experimental data were compared with the calculated results of the PHITS, MCNPX codes. All calculations give lower neutron energy spectra than the experimental ones for all targets above 20 MeV and must be improved for neutron production at 0-degree. These experimental data will be useful as benchmark data for investigating the accuracy of the Monte Carlo simulation and for the shielding design of accelerator facilities.

Journal Articles

Measurement of neutron spectra produced in the forward direction from thick graphite, Al, Fe and Pb targets bombarded by 350 MeV protons

Iwamoto, Yosuke; Taniguchi, Shingo*; Nakao, Noriaki*; Itoga, Toshio*; Nakamura, Takashi*; Nakane, Yoshihiro; Nakashima, Hiroshi; Satoh, Daiki; Yashima, Hiroshi*; Yamakawa, Hiroshi*; et al.

Nuclear Instruments and Methods in Physics Research A, 562(2), p.789 - 792, 2006/06

 Times Cited Count:6 Percentile:43.87(Instruments & Instrumentation)

Neutron energy spectra produced from thick targets play an important role in validation of calculation codes that are employed in the design of spallation neutron sources and the shielding design of accelerator facilities. However, appropriate experimental data were scarce in the forward direction for the incident energy higher than 100 MeV. In this study, neutron spectra at 0 degree from thick targets bombarded with 350 MeV protons were measured by the time-of-flight technique using an NE213. The targets used were graphite, Al, Fe and Pb and their thicknesses were chosen to be a little thicker than the stopping lengths. The experiment was carried out at the TOF course of the RCNP (Research Center of Nuclear Physics) ring cyclotron, Osaka University. The flight path length between center of the target and of an NE213 were 11.4 m for the measurement of low energy neutrons and 95 m for high energy neutrons. The experimental data are compared with the calculated results by using the Monte Carlo transport codes, such as MCNPX and PHITS codes.

JAEA Reports

Study on the neutron dosimetric characteristics of tissue equivalent proportional counter

Nunomiya, Tomoya*; Kim, E.*; Kurosawa, Tadahiro*; Taniguchi, Shingo*; Nakamura, Takashi*; Tsujimura, Norio; Momose, Takumaro; Shinohara, Kunihiko

JNC TY8400 99-007, 29 Pages, 1999/03

JNC-TY8400-99-007.pdf:1.31MB

None

Oral presentation

Thick target neutron yield at 0 degree by 250 and 350 MeV protons

Iwamoto, Yosuke; Taniguchi, Shingo*; Nakao, Noriaki*; Itoga, Toshio*; Nakamura, Takashi*; Nakane, Yoshihiro; Nakashima, Hiroshi; Satoh, Daiki; Yashima, Hiroshi*; Yamakawa, Hiroshi*; et al.

no journal, , 

Neutron energy spectra at 0 degree produced from stopping-length thick graphite, aluminum, iron and lead targets bombarded by 250 MeV and 350 MeV protons were measured at the neutron TOF course at RCNP of Osaka University. The neutron energy spectra were obtained by using the time-of-flight technique in the energy range from 10 MeV to incident proton energy. To compare the experimental data, Monte Carlo calculations by PHITS and MCNPX codes using the JENDL-HE and the LA150 evaluated files were performed. It was found that these calculation results at 0-degree generally underestimated the experimental data for all targets in the energy range above 20 MeV.

Oral presentation

Corrosion behavior of copper in environments containing sulfides

Watari, Shingo*; Kitayama, Ayami; Mitsui, Seiichiro; Taniguchi, Naoki; Kimura, Wataru*; Kajiyama, Hiroshi*

no journal, , 

The application of pure copper is being considered for the purpose of extending the life-time of disposal canisters in the direct disposal of spent fuel. Pure copper generally shows little corrosion development in aqueous solution environments with low oxygen concentrations due to its thermodynamic stability, but pure copper loses thermodynamic stability and corrosion develops depending on the sulfides conditions. In this study, immersion tests and U-bend tests were conducted to understand the corrosion progress behavior and stress corrosion cracking behavior of pure copper under the condition of sparging gas with various hydrogen sulfide concentrations to simulate the disposal environment where sulfide exists.

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