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Journal Articles

Microstructural evolution of intermetallic phase precipitates in Cr-coated zirconium alloy cladding in high-temperature steam oxidation up to 1400$$^{circ}$$C

Mohamad, A. B.; Nemoto, Yoshiyuki; Furumoto, Kenichiro*; Okada, Yuji*; Sato, Daiki*

Corrosion Science, 224, p.111540_1 - 111540_15, 2023/11

 Times Cited Count:0 Percentile:0(Materials Science, Multidisciplinary)

JAEA Reports

Nuclear Science Research Institute Meteorological Statistics (2017-2021)

Futagawa, Kazuo; Kashimura, Keita; Sato, Daiki*; Kawasaki, Masatsugu

JAEA-Data/Code 2022-011, 75 Pages, 2023/03

JAEA-Data-Code-2022-011.pdf:1.49MB

These statistical results are based on the meteorological data observed at the Nuclear Science Research Institute in Japan Atomic Energy Agency and statistically processed according to "The guideline of meteorological statistics for the safety analysis of nuclear power reactor" (Nuclear Safety Commission on January 28, 1982; revised on March 29, 2001). The statistics are based on 5 years of meteorological data, from January 2017 to December 2021. These are statistical results of wind direction, wind speed, atmospheric stability, etc., which are used for dose assessment of the general public due to radioactive materials discharged into the atmosphere from nuclear reactor facilities.

Journal Articles

Improvements in the particle and heavy-ion transport code system (PHITS) for simulating neutron-response functions and detection efficiencies of a liquid organic scintillator

Satoh, Daiki; Sato, Tatsuhiko

Journal of Nuclear Science and Technology, 59(8), p.1047 - 1060, 2022/08

 Times Cited Count:5 Percentile:84.97(Nuclear Science & Technology)

In this research, we simulated the neutron-response functions and detection efficiencies of a liquid organic scintillator using the particle and heavy-ion transport code system (PHITS). We incorporated the algorithm and database of the neutron-response simulation code SCINFUL-QMD into PHITS. Then, we updated the total, elastic, and inelastic cross-section data of the hydrogen and carbon nuclei for neutrons and developed a new scorer to analyze the light outputs from a scintillator. The calculation results of the neutron-response functions and the detection efficiencies were compared with results of SCINFUL-QMD, the previous PHITS with the new scorer, and the reported measurements. It was found that the improved PHITS successfully reproduced the results calculated by SCINFUL-QMD, except for around 150 MeV where a discontinuity of detection-efficiency curve was observed in the SCINFUL-QMD values. Our results showed better agreement with the measured data than the results of the previous PHITS. The uncertainties of the detection efficiencies calculated by PHITS using the present extensions were estimated to be approximately 15% for neutrons in the energy region below 100 MeV.

Journal Articles

Overview of accident-tolerant fuel R&D program in Japan

Yamashita, Shinichiro; Ioka, Ikuo; Nemoto, Yoshiyuki; Kawanishi, Tomohiro; Kurata, Masaki; Kaji, Yoshiyuki; Fukahori, Tokio; Nozawa, Takashi*; Sato, Daiki*; Murakami, Nozomu*; et al.

Proceedings of International Nuclear Fuel Cycle Conference / Light Water Reactor Fuel Performance Conference (Global/Top Fuel 2019) (USB Flash Drive), p.206 - 216, 2019/09

After the nuclear accident at Fukushima Daiichi Power Plant, research and development (R&D) program for establishing technical basis of accident-tolerant fuel (ATF) started from 2015 in Japan. Since then, both experimental and analytical studies necessary for designing a new light water reactor (LWR) core with ATF candidate materials are being conducted within the Japanese ATF R&D Consortium for implementing ATF to the existing LWRs, accompanying with various technological developments required. Until now, we have accumulated experimental data of the candidate materials by out-of-pile tests, developed fuel evaluation codes to apply to the ATF candidate materials, and evaluated fuel behavior simulating operational and accidental conditions by the developed codes. In this paper, the R&D progresses of the ATF candidate materials considered in Japan are reviewed based on the information available such as proceedings of international conference and academic papers, providing an overview of ATF program in Japan.

Journal Articles

Establishment of a novel detection system for measuring primary knock-on atoms

Tsai, P.-E.; Iwamoto, Yosuke; Hagiwara, Masayuki*; Sato, Tatsuhiko; Ogawa, Tatsuhiko; Satoh, Daiki; Abe, Shinichiro; Ito, Masatoshi*; Watabe, Hiroshi*

Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11

The energy spectra of primary knock-on atoms (PKAs) are essential for radiation damage assessment in design of accelerator facilities. However up to date the experimental data are still limited, due to the poor mass resolution and the high measurement threshold energies in the conventional setup of nuclear physics experiments using solid state detectors, which are typically above a few MeV/nucleon. In this study, a novel detection system consisting of two time detectors and one dE-E energy detector is proposed and being constructed to measure the PKA spectra. The system and detector design was based on Monte Carlo simulations by using the PHITS code. The PHITS simulations show that the system is able to distinguish the PKA isotopes above $$sim$$0.2-0.3 MeV/nucleon for A=20$$sim$$30 amu; the PKA mass identification thresholds decrease to $$<$$0.1 MeV/nucleon for PKAs lighter than 20 amu. The detection system will be tested in the summer of 2017, and the test results will be presented at the conference.

Journal Articles

Development of cement based encapsulation for low radioactive liquid waste in Tokai Reprocessing Plant

Matsushima, Ryotatsu; Sato, Fuminori; Saito, Yasuo; Atarashi, Daiki*

Proceedings of 3rd International Symposium on Cement-based Materials for Nuclear Wastes (NUWCEM 2018) (USB Flash Drive), 4 Pages, 2018/10

At TRP, LWTF was constructed as a facility for processing low radioactive liquid waste and solid waste generated at TRP, and a cold test is been carrying out. In this facility, initially, nitrate waste liquid after separation of nuclides generated with treatment of low radioactive liquid waste was to be solidified by using borate. However, at present, it is necessary to decompose the nitrate in the liquid waste to reduce the environmental burden. For the reason, as a plan to replace the nitrate with the carbonate and to make it as a cement based encapsulation, we are studying for the introduction of the facility. Currently, as a cement solidification technology development for this liquid waste, we are studying the application of cement material based on blast furnace slag (BFS) as a main component. In this report, we show the results of the test conducted on the actual scale (200 L drum can scale).

Journal Articles

Experimental analysis of neutron and background $$gamma$$-ray energy spectra of 80-400 MeV $$^{7}$$Li(p,n) reactions under the quasi-monoenergetic neutron field at RCNP, Osaka University

Iwamoto, Yosuke; Sato, Tatsuhiko; Satoh, Daiki; Hagiwara, Masayuki*; Yashima, Hiroshi*; Masuda, Akihiko*; Matsumoto, Tetsuro*; Iwase, Hiroshi*; Shima, Tatsushi*; Nakamura, Takashi*

EPJ Web of Conferences, 153, p.08019_1 - 08019_3, 2017/09

 Times Cited Count:0 Percentile:0.03(Nuclear Science & Technology)

To develop 100-400 MeV quasi-monoenergetic neutron field, we measured neutron and unexpected $$gamma$$-ray energy spectra of the $$^{7}$$Li(p,n) reaction with 80-389 MeV protons in the 100-m time-of-flight (TOF) tunnel at the Research Center for Nuclear Physics (RCNP). Neutron energy spectra with energies above 3 MeV were measured by the TOF method and $$gamma$$ energy spectra with energies above 0.1 MeV were measured by the automatic unfolding function of the radiation dose monitor DARWIN. For neutron spectra, the contribution of peak intensity to the total intensity integrated with energies above 3 MeV varied between 0.38 and 0.48. For $$gamma$$-ray spectra, high-energetic $$gamma$$-rays at around 70 MeV originated from the decay of $$pi$$$$^{0}$$ were observed over 200 MeV. For the 246-MeV proton incident reaction, the contribution of $$gamma$$-ray dose to neutron dose is negligible because the ratio of $$gamma$$-ray to neutron is 0.014.

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(Nuclear Science & Technology)

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

Applicability of the two-angle differential method to response measurement of neutron-sensitive devices at the RCNP high-energy neutron facility

Masuda, Akihiko*; Matsumoto, Tetsuro*; Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Sato, Tatsuhiko; Iwase, Hiroshi*; Yashima, Hiroshi*; Nakane, Yoshihiro; Nishiyama, Jun*; et al.

Nuclear Instruments and Methods in Physics Research A, 849, p.94 - 101, 2017/03

 Times Cited Count:1 Percentile:10.62(Instruments & Instrumentation)

Quasi-monoenergetic high-energy neutron fields induced by $$^{7}$$Li(p,n) reactions are used for the response evaluation of neutron-sensitive devices. The quasi-monoenergetic high-energy field consists of high-energy monoenergetic peak neutrons and unwanted continuum neutrons down to the low-energy region. A two-angle differential method has been developed to compensate for the effect of the continuum neutrons in the response measurements. In this study, the two-angle differential method was demonstrated for Bonner sphere detectors, which are typical examples of moderator-based neutron-sensitive detectors, to investigate the method's applicability and its dependence on detector characteristics. Through this study, the adequacy of the two-angle differential method was experimentally verified, and practical suggestions were made pertaining to this method.

Journal Articles

Characterization of high-energy quasi-monoenergetic neutron energy spectra and ambient dose equivalents of 80-389 MeV $$^{7}$$Li(p,n) reactions using a time-of-flight method

Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Araki, Shohei*; Yashima, Hiroshi*; Sato, Tatsuhiko; Masuda, Akihiko*; Matsumoto, Tetsuro*; Nakao, Noriaki*; Shima, Tatsushi*; et al.

Nuclear Instruments and Methods in Physics Research A, 804, p.50 - 58, 2015/12

 Times Cited Count:23 Percentile:87.12(Instruments & Instrumentation)

We have measured neutron energy spectra for the 80, 100 and 296 MeV proton incident reactions at the RCNP cyclotron facility using time-of-flight method. The neutron energy spectrum consisted of the peak and continuum parts and the peak intensity was 0.9-1.1 $$times$$ 10$$^{10}$$ neutrons/sr/$$mu$$C. The ratio of peak intensity of the spectrum to the total intensity was between 0.38 and 0.48. To consider the correction required to derive a response in the peak region from the measured total response for neutron monitors, we proposed the subtraction method using energy spectra between 0$$^{circ}$$ and 25$$^{circ}$$. The normalizing factor k against the 25$$^{circ}$$ neutron fluence that equalizes the 0$$^{circ}$$ neutron fluence in the continuum region was from 0.74 to 1.02. With our previous results, we have obtained data for characterization of monoenergetic neutron field for the $$^{7}$$Li(p,n) reaction with 80$$sim$$389 MeV protons at the RCNP cyclotron facility.

Journal Articles

Energy-dependent fragmentation cross sections of relativistic $$^{12}$$C

Ogawa, Tatsuhiko; Sato, Tatsuhiko; Hashimoto, Shintaro; Satoh, Daiki; Tsuda, Shuichi; Niita, Koji*

Physical Review C, 92(2), p.024614_1 - 024614_14, 2015/08

AA2015-0260.pdf:2.96MB

 Times Cited Count:44 Percentile:92.28(Physics, Nuclear)

For prediction of radiological impact of heavy ions in accelerator facilities, space missions and cancer therapy, nuclear reaction models play a fundamental role. As one of such models, JAERI Quantum molecular dynamics (JQMD) has been successfully used to describe production of residue and secondary particles in nucleus-nucleus collisions. However, it has been pinpointed that JQMD underestimates projectile-like fragments produced in peripheral collisions. Moreover, no cross section data systematically measured over a wide energy range are not available, which makes it difficult to benchmark the reaction models. In this study, we develop a method to measured fragmentation cross sections using a thick target and detecting fragments produced from incident ions fragmented in the target using telescope detectors. Thus we obtained fragmentation cross sections systematically over a wide energy range. We also revise the description of reaction mechanism and ground-state nuclear structure in JQMD to take into account for peripheral collisions accurately. So far, ground-state nuclei got excited and sometimes disintegrated owing to frame transform from the laboratory system to the center-of-mass system. Fragment production cross sections calculated by the revised JQMD (JQMD2.0) are in better agreement with the literature data.

Journal Articles

Response measurement of various neutron dose equivalent monitors in 134-387 MeV neutron fields

Nakane, Yoshihiro; Hagiwara, Masayuki*; Iwamoto, Yosuke; Iwase, Hiroshi*; Satoh, Daiki; Sato, Tatsuhiko; Yashima, Hiroshi*; Matsumoto, Tetsuro*; Masuda, Akihiko*; Nunomiya, Tomoya*; et al.

Progress in Nuclear Science and Technology (Internet), 4, p.704 - 708, 2014/04

no abstracts in English

Journal Articles

Measurement of deposit energy distribution of heavy ions using a wall-less tissue equivalent proportional counter

Tsuda, Shuichi; Sato, Tatsuhiko; Satoh, Daiki; Takada, Masashi*

HIMAC-138, p.225 - 226, 2012/08

Radial dose distribution for 290 MeV/u carbon and 500 MeV/u iron ions were measured. It is found experimentally that radial dose distributions depend on the distance from the incident beam trajectory.

Journal Articles

Systematic measurement of lineal energy distributions for proton, He and Si ion beams over a wide energy range using a wall-less tissue equivalent proportional counter

Tsuda, Shuichi; Sato, Tatsuhiko; Takahashi, Fumiaki; Satoh, Daiki; Sasaki, Shinichi*; Namito, Yoshihito*; Iwase, Hiroshi*; Ban, Shuichi*; Takada, Masashi*

Journal of Radiation Research, 53(2), p.264 - 271, 2012/04

 Times Cited Count:14 Percentile:55.77(Biology)

Deposit energy distribution in microscopic site is basic information for understanding of biological effects of energetic heavy ion beams. To estimate RBE, lineal energy, $$y$$, can be an appropriate physical index. In this work, a wall-less tissue equivalent proportional counter has been designed and used for the measurement of $$y$$ distributions, $$y$$$$f$$($$y$$), for 160 MeV H, 150 MeV/u He, 290 MeV/u C, 490 MeV/u Si and 500 MeV/u Ar. Data of $$y$$$$f$$($$y$$) were also obtained in the wide range of LET. The dose-means of $$y$$, $$overline{y}$$$$_{D}$$, were compared with those calculated by the microdosimetric function of PHITS. It is found that the calculated $$y$$$$f$$($$y$$) and $$overline{y}$$$$_{D}$$ agree fairly well with those measured. The values of $$overline{y}$$$$_{D}$$ are larger than those of LET less than $$sim$$10 keV/$$mu$$m because of the discrete energy deposition by delta rays, while the relation is reversed above 10 keV/$$mu$$m. The results indicate that care should be taken in the difference between $$overline{y}$$$$_{D}$$ and LET when the values of RBE of energetic heavy ions are estimated.

Journal Articles

Response measurement of a Bonner sphere spectrometer for high-energy neutrons

Masuda, Akihiko*; Matsumoto, Tetsuro*; Harano, Hideki*; Nishiyama, Jun*; Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Iwase, Hiroshi*; Yashima, Hiroshi*; Nakamura, Takashi*; et al.

IEEE Transactions on Nuclear Science, 59(1), p.161 - 166, 2012/02

 Times Cited Count:12 Percentile:66.54(Engineering, Electrical & Electronic)

In this study, responses of Bonner sphere spectrometer (BSS) for 245 and 388 MeV neutrons was measured at RCNP, Osaka University. The neutrons are generated in the $$^{7}$$Li(p,n) reaction and its spectra consist of a high-energy peak and a continuum down to the low energy. Therefore, the observed counts of BSS caused by the continuum need to be subtracted. Adjusting a Li target angle and a collimator position, 0 deg and 30 deg component of generated neutron are available. While the 0 deg component contains both the peak and the continuum, the 30 deg component is considered to contain only the continuum. Therefore, the response of the peak is obtained. The spectra were measured using the time-of-flight (TOF) method with a NE213 scintillator.

JAEA Reports

Construction of average adult Japanese voxel phantoms for dose assessment

Sato, Kaoru; Takahashi, Fumiaki; Satoh, Daiki; Endo, Akira

JAEA-Data/Code 2011-013, 87 Pages, 2011/12

JAEA-Data-Code-2011-013.pdf:8.12MB

ICRP adopted the adult reference phantoms based on the Caucasian data. In future, the dosimetric quantities calculated using these phantoms will be used for the radiation protection. However, there are some cases that the anatomical characteristics influence the organ doses. Therefore, it is needed to consider the anatomical characteristics of the subjects. Since the body sizes and organ masses of adult Japanese are smaller than those of adult Caucasian, the authors constructed the averaged adult male and female phantoms by modifying the previously developed JM and JF Japanese phantoms. In modification processes, (1) the body sizes were agreed with the Japanese averages; (2) the organ masses were adjusted to the Japanese averages within 10%, and (3) the organs, which were newly added for evaluation of the effective dose in ICRP Publ.103, were modeled. This report describes the construction, and anatomical and dosimetric characteristics of the newly constructed Japanese phantoms.

Journal Articles

Measurement of lineal energy distribution of heavy ion using wall-less tissue equivalent proportional counter

Tsuda, Shuichi; Sato, Tatsuhiko; Takahashi, Fumiaki; Satoh, Daiki; Sasaki, Shinichi*; Namito, Yoshihito*; Iwase, Hiroshi*; Ban, Shuichi*; Takada, Masashi*

KEK Proceedings 2011-8, p.100 - 108, 2011/12

Deposit energy distribution in microscopic site is basic information for understanding of biological effects of energetic heavy ion beams. To estimate RBE, lineal energy, y, can be an appropriate physical index. In this work, a wall-less tissue equivalent proportional counter has been designed and used for the measurement of y distributions, $$yf(y)$$, for 160 MeV H, 150 MeV/u He and 490 MeV/u Si ion beams. Data of $$yf(y)$$ and the dose-means of $$y$$, $$overline{y}_D$$, were compared with those calculated by the microdosimetric function of PHITS. It is found that the calculated $$yf(y)$$ and $$overline{y}_D$$ agree fairly well with those measured, as well as the already reported result of 290 MeV/u carbon beam.

Journal Articles

Measurement of deposit energy distribution of heavy ions using a wall-less tissue equivalent proportional counter

Tsuda, Shuichi; Sato, Tatsuhiko; Satoh, Daiki; Takahashi, Fumiaki; Sasaki, Shinichi*; Namito, Yoshihito*; Sanami, Toshiya*; Saito, Kiwamu*; Takada, Masashi*

HIMAC-136, p.219 - 220, 2011/11

Measurements of lineal energy distribution were employed using 160 MeV proton and 490 MeV/u Si. The calculated $$yf(y)$$ by PHITS and $$overline{y}_D$$ agree fairly well with those measured. The LET dependence of $$overline{y}_D$$ was obtained from 3 to 300 keV/um in this project.

Journal Articles

Upgrades of DARWIN; A Dose and spectrum monitoring system applicable to various types of radiation over wide energy ranges

Sato, Tatsuhiko; Satoh, Daiki; Endo, Akira; Shigyo, Nobuhiro*; Watanabe, Fusao*; Sakurai, Hiroki*; Arai, Yoichi*

Nuclear Instruments and Methods in Physics Research A, 637(1), p.149 - 157, 2011/05

 Times Cited Count:6 Percentile:44.28(Instruments & Instrumentation)

A dose and spectrum monitoring system applicable to neutrons, photons and muons over wide ranges of energy, designated as DARWIN, has been developed for radiological protection in high-energy accelerator facilities. The performance of the upgraded DARWIN was examined in various radiation fields, including an operational field in J-PARC. The experiments revealed that the dose rates and spectra measured by the upgraded DARWIN are quite reasonable, even in radiation fields with peak structures in terms of both spectrum and time variation. These results clearly demonstrate the usefulness of DARWIN for improving radiation safety in high-energy accelerator facilities.

Journal Articles

Characterisation of quadi-monoenergetic neutron energy spectra using $$^{7}$$Li(p,n) reactions at 246-389 MeV

Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Iwase, Hiroshi*; Yashima, Hiroshi*; Itoga, Toshiro*; Sato, Tatsuhiko; Nakane, Yoshihiro; Nakashima, Hiroshi; Sakamoto, Yukio; et al.

Proceedings of 10th Meeting of the Task Force on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-10), p.53 - 61, 2011/03

The neutron energy spectra penetrating 10 to 100 cm thick iron and 25 to 200 cm thick concrete shields have been measured using 138, 243 and 387 MeV quasi-monoenergetic neutron sources at the Research Center for Nuclear Physics (RCNP) facility, Osaka University. The source neutrons were produced from a 1 cm thick lithium target bombarded with 140, 245 and 388 MeV protons. Two types of NE213 liquid organic scintillators and Bonner ball neutron spectrometers were used for the neutron energy spectrum measurement. The TOF and unfolding methods were applied to estimate the energy spectra behind the shield in the peak energy region and continuous energy region, respectively. We have also measured the neutron energy spectra and angular distribution of the source neutron above 1 MeV in the angular range from 0$$^{circ}$$ to 30$$^{circ}$$ with the TOF method. All measured data were compared with the PHITS Monte Carlo calculations.

101 (Records 1-20 displayed on this page)