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Meigo, Shinichiro; Nakano, Keita*; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*
EPJ Web of Conferences, 284, p.05001_1 - 05001_4, 2023/05
Times Cited Count:1 Percentile:72.33(Nuclear Science & Technology)In high-intensity proton accelerator facilities such as Accelerator Driven System (ADS) and the spallation neutron source, it is crucial to evaluate the damage of beam-interception materials and accelerator components, such as a magnet coil. The displacement per atom (dpa) is used as a damage index, which is derived by integrating the particle flux and the displacement cross section based on the NRT model. Although the dpa is employed as the standard, the experimental data of displacement cross section are scarce for a proton in the energy region above 20 MeV. To obtain the data for superconducting materials for high-intensity accelerators and magnets, the displacement cross section of Nb for proton irradiation with a kinetic energy range between 0.4 and 3 GeV was measured. For sustaining damage in the sample, the Nb sample was cooled at a cryogenic temperature (8 K), where the recombination of Frenkel pairs due to thermal motion was well suppressed with maintaining the normal conductivity to maintain Matthiessen's rule. The displacement cross section of Nb was calculated using the PHITS code, and was compared with the present experimental results. It was found that the widely utilized NRT model overestimates the cross section by a factor of 2, as suggested by the previous works. It was also found that the calculation with a recently proposed athermal recombination corrected (arc) model based on Molecular Dynamics (MD) shows good agreement with the present data.
Meigo, Shinichiro; Iwamoto, Yosuke; Matsuda, Hiroki
Isotope News, (774), p.27 - 31, 2021/04
no abstracts in English
Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*; Hasegawa, Shoichi; Maekawa, Fujio; Iwamoto, Hiroki; Nakamoto, Tatsushi*; Ishida, Taku*; Makimura, Shunsuke*
JPS Conference Proceedings (Internet), 33, p.011050_1 - 011050_6, 2021/03
R&D of the beam window is crucial in the ADS, which serves as a partition between the accelerator and the target region. Although the displacement per atom (DPA) is used to evaluate the damage on the window, experimental data on the displacement cross section is scarce in the energy region above 20 MeV. We started to measure the displacement cross section for the protons in the energy region between 0.4 to 3 GeV. The displacement cross section can be derived by resistivity change divided by the proton flux and the resistivity change per Frankel pair on cryo-cooled sample to maintain damage. Experiments were conducted at the 3 GeV proton synchrotron at the J-PARC Center, and aluminum and copper was used as samples. As a result of comparison between the present experiment and the calculation of the NRT model, which is widely used for calculation of the displacement cross section, it was found that the calculation of the NRT model overestimated the experiment by about 3 times.
Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*; Hasegawa, Shoichi; Maekawa, Fujio; Iwamoto, Hiroki; Nakamoto, Tatsushi*; Ishida, Taku*; Makimura, Shunsuke*
EPJ Web of Conferences, 239, p.06006_1 - 06006_4, 2020/09
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)R&D of the beam window is crucial in the ADS, which serves as a partition between the accelerator and the target region. Although the displacement per atom (DPA) is used to evaluate the damage on the window, experimental data on the displacement cross section is scarce in the energy region above 20 MeV. We started to measure the displacement cross section for the protons in the energy region between 0.4 to 3 GeV. The displacement cross section can be derived by resistivity change divided by the proton flux and the resistivity change per Frankel pair on cryo-cooled sample to maintain damage. Experiments were conducted at the 3 GeV proton synchrotron at the J-PARC Center, and copper was used as samples. As a result of comparison between the present experiment and the calculation of the NRT model, which is widely used for calculation of the displacement cross section, it was found that the calculation of the NRT model overestimated the experiment by about 3 times.
Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*; Hasegawa, Shoichi; Maekawa, Fujio; Iwamoto, Hiroki; Nakamoto, Tatsushi*; Ishida, Taku*; Makimura, Shunsuke*
JPS Conference Proceedings (Internet), 28, p.061004_1 - 061004_6, 2020/02
no abstracts in English
Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Iwamoto, Hiroki; Hasegawa, Shoichi; Maekawa, Fujio; Yoshida, Makoto*; Ishida, Taku*; Makimura, Shunsuke*; Nakamoto, Tatsushi*
Proceedings of 9th International Particle Accelerator Conference (IPAC '18) (Internet), p.499 - 501, 2018/06
no abstracts in English
Konno, Chikara; Sato, Satoshi; Ota, Masayuki; Kwon, Saerom; Ochiai, Kentaro
Fusion Engineering and Design, 109-111(Part B), p.1649 - 1652, 2016/11
Times Cited Count:8 Percentile:57.10(Nuclear Science & Technology)Recently we have examined KERMA factors and DPA cross section data in the latest official ACE files of JENDL-4.0, ENDF/B-VII.1, JEFF-3.2 and FENDL-3.0 in more detail and we found out the following new problems on the KERMA factors and DPA cross section data. (1) NJOY bugs and incorrect nuclear data generated KERMA factors and DPA cross section data of no increase with decreasing neutron energy in low neutron energy. (2) Huge helium production data caused drastically large KERMA factors and DPA cross section data in low neutron energy. (3) It seemed that NJOY could not adequately process capture cross section data in File 6, not File 12-15. (4) KERMA factors with the kinematics method are not correct for nuclear data libraries without detailed secondary particle data (energy-angular distribution data). These problems should be resolved based on our study.
Nordlund, K.*; Sand, A. E.*; Granberg, F.*; Zinkle, S. J.*; Stoller, R.*; Averback, R. S.*; Suzudo, Tomoaki; Malerba, L.*; Banhart, F.*; Weber, W. J.*; et al.
NEA/NSC/DOC(2015)9 (Internet), 86 Pages, 2015/00
Within this report, we review the current understanding of primary radiation damage from neutrons, ions and electrons with emphasis on the range of validity of the dpa concept in all main classes of materials, and in particular discuss known shortcomings. We recognise that the current NRT-dpa standard is fully valid in the sense of a scaled radiation exposure measure, as it is essentially proportional to the radiation energy deposited per volume. As such, it is highly recommended to be used in reporting neutron damage results to enable comparison between different nuclear reactor environments and ion irradiations. However, in the sense of a measure of damage production the NRT-dpa value has several well-known problems. We discuss this matter and propose an improved dpa definition.
Morita, Yasuji; Kubota, Masumitsu*
JAERI-Review 2005-041, 35 Pages, 2005/09
Research and development on Partitioning in JAERI are reviewed in the present report from the beginning to the development of the 4-Group Partitioning Process and its test with real high-level liquid waste (HLLW). In the 3-Group Partitioning Process established in around 1980, elements in HLLW are separated into 3 groups of transuranium element group, Sr-Cs group and the other element group. The 4-Group Partitioning Process subsequently developed contains the separation of Tc-platinum group metals additionally. The process was tested to demonstrate its performance with real concentrated HLLW. Until then, various separation methods for various elements were studied and selection and optimization of the separation methods were carried out to establish the process. Review of the experience, findings and results is very important and valuable for future study on partitioning. The present report is prepared from this point of view.
Harada, Masahide; Watanabe, Noboru; Konno, Chikara; Meigo, Shinichiro; Ikeda, Yujiro; Niita, Koji*
Journal of Nuclear Materials, 343(1-3), p.197 - 204, 2005/06
Times Cited Count:31 Percentile:87.27(Materials Science, Multidisciplinary)For a construction of maintenance and storage scenarios for JSNS, lives of structure material need to be estimated. DPA (Displacement per Atom) was a major index of radiation damage. So we evaluated DPA value of each component. Function of the DPA calculation was equipped to the PHITS code, which was particle and heavy ion transport code. For DPA calculation, displacement cross section was necessary. Displacement cross sections of neutron below 150 MeV were processed by the NJOY code from LA150 library and those of neutron above 150MeV and proton in the all energy region were obtained from energies of fragments calculated in the PHITS. By using the PHITS, we calculated DPA values and DPA mapping. We obtained that the peak DPA values at end of 5000MWh operation were 4.1 for target vessel, 2.8 for reflector and moderator vessels, and 0.4 for proton beam windows, respectively. We estimated the target life at 1 year and the moderator life at 6 year.
Ando, Masami; Wakai, Eiichi; Sawai, Tomotsugu; Tanigawa, Hiroyasu; Furuya, Kazuyuki; Jitsukawa, Shiro; Takeuchi, Hiroshi; Oka, Keiichiro*; Onuki, Somei*; Koyama, Akira*
Journal of Nuclear Materials, 329-333(2), p.1137 - 1141, 2004/08
Times Cited Count:54 Percentile:94.31(Materials Science, Multidisciplinary)One of the most crucial issues on R&D of reduced activation ferritic/martensitic steels is the effect of helium on the degradation of fracture toughness. The synergistic effects of displacement damage and helium on F82H steel can be partially simulated by martensitic steels doped with B or
Ni in a mixed spectrum fission reactor. However, the control of helium production rate is difficult and the chemical effects of B or Ni doping on mechanical property are not small. Therefore, multi-ion irradiation method is the most convenient and accurate method to simulate various irradiation conditions. Moreover, the effects of helium on irradiation hardening behavior can be examined by combining ion-irradiation with ultra micro-indentation technique. The purpose of this study is to examine the extra component of radiation hardening due to implanted helium in F82H. The extra component of irradiation hardening due to helium was hardly detected in the dual-beam irradiation. Therefore, the effect on irradiation hardening below 630K of helium (
500 appm) was very small.
Futakawa, Masatoshi; Kurata, Yuji; Henry, J.*; Ioka, Ikuo; Saito, Shigeru; Naito, Akira
FZKA-6876, p.166 - 171, 2003/12
A report at MEGAPIE(Megawatt Pilot Experiment) Technical R & D Meeting is collected into an FZK report. Triple ion beam irradiation tests on T91 specimens were conducted under MEGAPIE condition using TIARA facility at JAERI. Results of triple ion beam irradiation up to 15dpa, 1400appm He, 10000appm H at 320C were compared with those of single or dual beam irradiation of Fe or He ions by use of a micro-indentation method. Hardsness increase was mainly attributed to displacement damage by Fe ions. A little effect on hardness was found on simultaneous implantation of He and H ions. An analysis method to predict mechanical characterization form micro-indentation test results was developed on ion irradiated materials.
Morita, Yasuji; Tachimori, Shoichi; Koma, Yoshikazu*; Aoshima, Atsushi*
JAERI-Research 2002-017, 20 Pages, 2002/08
The present report describes the results of a joint study between Japan Nuclear Cycle Development Institute (JNC) and Japan Atomic Energy Research Institute (JAERI) on actinide separation process from high-level liquid waste. The purpose of the joint study is to point out common subjects in process development by an overall evaluation of each actinide separation process: TRUEX/SETFICS Process studied in JNC and DIDPA Extraction Process studied in JAERI. The result of the evaluation showed that both processes have common subjects to be studied in sub-processes such as treatment step for spent solvent or DTPA waste solution and solvent washing step for recycling, although the main process is different from each other. It is necessary to develop the sub-processes and to test the whole process including the sub-processes. Two essential requirements: the cost reduction and the minimization of secondary wastes, are very important in future research and development for more rational and effective actinide separation process.
Watanabe, Masayuki; Tatsugae, Ryozo*; Morita, Yasuji; Kubota, Masumitsu*
Journal of Radioanalytical and Nuclear Chemistry, 252(1), p.53 - 57, 2002/04
Times Cited Count:7 Percentile:43.62(Chemistry, Analytical)no abstracts in English
Murakami, Yoshiki*; Amano, Tsuneo*; Shimizu, Katsuhiro; Shimada, Michiya; Ogawa, Yuichi*
JAERI-Research 2001-049, 58 Pages, 2001/11
no abstracts in English
Watanabe, Masayuki; Tatsugae, Ryozo*; Shirahashi, Koichi; Morita, Yasuji; Kubota, Masumitsu*
Journal of Radioanalytical and Nuclear Chemistry, 250(2), p.377 - 379, 2001/11
Times Cited Count:7 Percentile:48.26(Chemistry, Analytical)no abstracts in English
Nagao, Yoshiharu; Takemoto, Noriyuki; Takeda, Takashi
JAERI-Tech 2001-069, 83 Pages, 2001/10
no abstracts in English
Kikuchi, Kenji; Kogawa, Hiroyuki; Sasa, Toshinobu
JAERI-Conf 2001-002, p.1251 - 1258, 2001/03
no abstracts in English
Shimakawa, Satoshi; Nagao, Yoshiharu; Fujiki, Kazuo
Reactor Dosimetry: Radiation Metrology and Assessment (ASTM STP 1398), p.244 - 251, 2001/00
no abstracts in English
Fukahori, Tokio; Chiba, Satoshi; Shibata, Keiichi; Ikeda, Yujiro; Aruga, Takeo; Watanabe, Yukinobu*; Murata, Toru*; Yamano, Naoki*; Kawai, Masayoshi*
Reactor Dosimetry: Radiation Metrology and Assessment (ASTM STP 1398), p.591 - 598, 2001/00
no abstracts in English