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Murata, Isao*; Takagi, Satoshi*; Kondo, Keitaro; Shiken, Kimiaki*; Miyamaru, Hiroyuki*; Mitsuda, Motoyuki; Maekawa, Fujio; Ochiai, Kentaro; Nishitani, Takeo
Nuclear Instruments and Methods in Physics Research A, 595(2), p.439 - 446, 2008/10
Times Cited Count：4 Percentile：33.9(Instruments & Instrumentation)A technique was developed to measure the angle-correlated neutron energy spectrum with the coincidence detection technique using a pencil-beam DT neutron source at the Fusion Neutronics Source (FNS) of the Japan Atomic Energy Agency (JAEA). Triple differential cross-sections of the 
Mn(n,2n) reaction were measured first, from which the total Mn(n,2n) reaction cross-section was deduced and compared with JENDL-3.3. The agreement was sufficient to prove the validity of the technique. With the present measuring technique, a complete measurement of a medium-heavy or heavy element such as manganese would become possible through several measurements, because the angle dependence of the emitted neutrons from it is normally weak. The technique will be a useful tool for measuring the angle-correlated neutron spectrum of light elements such as beryllium for investigation of their complicated nuclear reaction mechanism.
Be(n,2n) reaction with a pencil-beam DT neutron sourceMurata, Isao*; Takagi, Satoshi*; Shiken, Kimiaki*; Kondo, Keitaro; Miyamaru, Hiroyuki*; Ochiai, Kentaro; Nishitani, Takeo; Konno, Chikara
Proceedings of International Conference on Nuclear Data for Science and Technology (ND 2007), Vol.2, p.999 - 1002, 2008/05
The (n,2n) reaction plays a very important role in the design of fusion reactor. In the present study, using a pencil-beam DT neutron source, angle-correlated two neutrons emitted through (n,2n) reaction have directly been measured to determine (n,2n) reaction cross section with the coincidence detection technique for beryllium which is the most important element in the fusion reactor. In the experiment, two NE213 detectors were arranged very close to the sample to efficiently measure the two neutrons. The measured spectra were unfolded by FORIST with the detector response matrix evaluated by SCINFUL. As a relust, comparing with the evaluations of ENDF/B-VI and JENDL-3.3 for energies above 800 keV of the lower measurable limit energy, the shape of derived angula-differential cross-section fits JENDL-3.3 better than ENDF/B-VI. However, agreement of the cross section of (n,2n) above 800 keV was acceptable within 10 percents for both libraries.
Kondo, Keitaro; Murata, Isao*; Ochiai, Kentaro; Kubota, Naoyoshi; Miyamaru, Hiroyuki*; Takagi, Satoshi*; Shido, Shoichi*; Konno, Chikara; Nishitani, Takeo
Fusion Engineering and Design, 82(15-24), p.2786 - 2793, 2007/10
Times Cited Count：2 Percentile：18.73(Nuclear Science & Technology)no abstracts in English
Kondo, Keitaro; Murata, Isao*; Ochiai, Kentaro; Miyamaru, Hiroyuki*; Kubota, Naoyoshi; Takagi, Satoshi*; Shido, Shoichi*; Takahashi, Akito*; Nishitani, Takeo
Nuclear Instruments and Methods in Physics Research A, 568(2), p.723 - 733, 2006/12
Times Cited Count：15 Percentile：70.56(Instruments & Instrumentation)Deuteron-tritium (DT) neutron induced charged-particle emission double-differential cross section (DDXc) is quite important to estimate nuclear heating, material damages for a fusion reactor. In order to realize the accurate measurement of the DDXc data especially for light nuclei, we propose a unique spectrometer system and a data processing method in this paper. The spectrometer overcomes the fundamental difficulty of the DDXc measurement with a pencil-beam neutron source and a counter telescope consisting of silicon surface barrier detectors. A superior S/N ratio, fine energy and angular resolutions, a wide detection energy range, and a excellent particle discrimination are realized. In order to confirm the validity of the spectrometer, measurements of the emitted 
-particle from 
Al(
) reaction and the recoiled proton from 
H(
) reaction are carried out. Based on the results, we conclude the validity and the superiority of the present spectrometry technique.
Kondo, Keitaro; Takagi, Satoshi*; Murata, Isao*; Miyamaru, Hiroyuki*; Takahashi, Akito*; Kubota, Naoyoshi; Ochiai, Kentaro; Nishitani, Takeo
Fusion Engineering and Design, 81(8-14), p.1527 - 1533, 2006/02
Times Cited Count：14 Percentile：68.12(Nuclear Science & Technology)In a fusion reactor development, double-differential charged-particle emission cross sections(DDXc) are necessary to estimate nuclear heating and material damages of candidate materials irradiated with neutrons. Especially in light nuclei such as Be, Li, and C, nuclear reactions are complicated and difficult to estimate energy spectra of emitted particles based only on theoretical calculations Therefore development of a new technique for precise measurements of DDXc is quite important. Recently we successfully developed a new spectrometer for measurement of DDXc using a pencil-beam DT neutron source of FNS in JAERI. In the present study we carried out measurements of DDXc of Be, 
C, 
F, and Al using the spectrometer. The present technique was valid from the result of measurement for the Al(n,x) reactions. Slight differences appeared between measured data and evaluation or previous experimental values for Be(n,x) reactions at backward scattering angle and in lower energy region.
Kondo, Keitaro; Takagi, Satoshi*; Shiken, Kimiaki*; Shido, Shoichi*; Murata, Isao*; Miyamaru, Hiroyuki*; Ochiai, Kentaro; Kubota, Naoyoshi; Nishitani, Takeo
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no abstracts in English
Shiken, Kimiaki*; Takagi, Satoshi*; Kondo, Keitaro; Matsunaka, Masayuki*; Murata, Isao*; Miyamaru, Hiroyuki*; Ochiai, Kentaro; Nishitani, Takeo
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no abstracts in English
Shibuya, Kentaro*; Uchimoto, Tetsuya*; Takagi, Toshiyuki*; Takaya, Shigeru
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Magnetic property of aged samples and creep rupture samples of mod. 9Cr-1Mo steel were measured by a nonlinear eddy current method and a magnetic Kerr effect method. Concerning the creep rupture samples, it was found that the equivalent remanent magnetization measured by the nonlinear eddy current method and that measured by the magnetic Kerr effect method are different. This difference may be introduced by change in precipitation of MX carbonnitride and dislocation.
Liang, N.*; Chiang, P.-N.*; Wang, Y.*; Teramoto, Munemasa*; Takagi, Kentaro*; Kondo, Toshiaki*; Koarashi, Jun; Zhang, Y.*; Li, S.*; Fang, J.*; et al.
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Takagi, Kentaro*; Liang, N.*; Aguilos, M.*; Teramoto, Munemasa*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko
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Kondo, Toshiaki*; Teramoto, Munemasa*; Nakane, Kaneyuki*; Takagi, Kentaro*; Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Masahiro*; Ishida, Sachinobu*; Liang, N.*
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Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Kentaro*; Kondo, Toshiaki*; Teramoto, Munemasa*; Nagano, Hirohiko; Kokubu, Yoko; Takagi, Masahiro*; Ishida, Sachinobu*; Hiradate, Shuntaro*; et al.
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no abstracts in English
Takagi, Kentaro*; Liang, N.*; Aguilos, M.*; Kira, R.*; Teramoto, Munemasa*; Kobayashi, Makoto*; Sun, L.*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko
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no abstracts in English
Kondo, Toshiaki*; Teramoto, Munemasa*; Takagi, Kentaro*; Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Masahiro*; Ishida, Sachinobu*; Liang, N.*
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no abstracts in English
Atarashi-Andoh, Mariko; Koarashi, Jun; Takagi, Kentaro*; Kondo, Toshiaki*; Teramoto, Munemasa*; Nagano, Hirohiko; Kokubu, Yoko; Takagi, Masahiro*; Ishida, Sachinobu*; Liang, N.*
no journal, ,
no abstracts in English
Liang, N.*; Takahashi, Yoshiyuki*; Teramoto, Munemasa*; Zhao, X.*; Tomimatsu, Hajime*; Takagi, Kentaro*; Hirano, Takashi*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko; et al.
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no abstracts in English
Takagi, Kentaro*; Liang, N.*; Aguilos, M.*; Rythi, K.*; Teramoto, Munemasa*; Kobayashi, Makoto*; Sun, L.*; Kondo, Toshiaki*; Koarashi, Jun; Atarashi-Andoh, Mariko
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Koarashi, Jun; Atarashi-Andoh, Mariko; Takagi, Kentaro*; Kondo, Toshiaki*; Teramoto, Munemasa*; Nagano, Hirohiko; Kokubu, Yoko; Takagi, Masahiro*; Ishida, Sachinobu*; Hiradate, Shuntaro*; et al.
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It is possible that global warming will promote the decomposition of soil organic carbon (SOC) and cause further global warming. In this study, the quantity and quality of SOC (carbon and nitrogen content, stable and radioactive carbon isotope composition, etc.) were investigated in warming and control plots at five forest sites in Japan, where long-term soil warming experiments have been conducted. Results show no remarkable difference in the quantity and quality of SOC stored in surface (0-20 cm) soils between the warming and control plots, suggesting the warming-induced increase in the soil respiration will continue over the next decade, probably due to the abundant SOC storage in Japanese forest surface soils.
Atarashi-Andoh, Mariko; Koarashi, Jun; Takagi, Kentaro*; Kondo, Toshiaki*; Teramoto, Munemasa*; Nagano, Hirohiko; Kokubu, Yoko; Takagi, Masahiro*; Ishida, Sachinobu*; Liang, N.*
no journal, ,
Profiles of soil organic matter (SOM) can show striking patterns of carbon and nitrogen isotopic enrichment with increasing depth. Although various factors are involved in the distribution of stable isotope ratios in forest ecosystems, the variation in isotope ratios in SOM is caused by isotopic discrimination during microbially driven processing. Therefore, analyses of the carbon and nitrogen isotope ratios in SOM provide insights into the dynamics and accumulation of the SOM. This study measured the carbon and nitrogen isotope ratios of soil collected in warming and control plots in five forests in Japan, where long-term warming experiments have been conducted. This showed clear differences in SOM quality among the five forests. There was no remarkable difference in the isotope compositions of the warming and control plots, indicating that there has been no marked change in SOM after a decade of warming, probably due to the abundant SOM storage in Japanese forest surface soils.
Liang, N.*; Zhang, Y.*; Chiang, P.-N.*; Lai, D.*; Teramoto, Munemasa*; Takagi, Kentaro*; Kondo, Toshiaki*; Koarashi, Jun; Wang, Y.*; Li, S.*; et al.
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