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Komeda, Masao; Toh, Yosuke; Tanabe, Kosuke*; Kitamura, Yasunori*; Misawa, Tsuyoshi*
Annals of Nuclear Energy, 159, p.108300_1 - 108300_8, 2021/09
Times Cited Count：2 Percentile：31.78(Nuclear Science & Technology)Kitamura, Yasunori*; Fukushima, Masahiro; Kitamura, Yasunori*
Annals of Nuclear Energy, 125, p.328 - 341, 2019/01
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)It has been taken for granted that the neutron correlation methods that employ two sets of neutron counting systems, e.g., the covariance-to-mean and the cross-correlation methods, are free from the count-loss effect for determination of the neutron decay constant. It was however found in the present study that these methods overestimate the neutron decay constant under high counting rate conditions. New formulae of these methods were hence obtained on the basis of a rigorous theoretical approach for treating the count-loss process. It is expected that the present formulae work better than conventional ones for determination of the neutron decay constant.
Kitamura, Yasunori*; Fukushima, Masahiro
Nuclear Science and Engineering, 186(2), p.168 - 179, 2017/05
Times Cited Count：1 Percentile：10.62(Nuclear Science & Technology)An inconsistency between the reactivity worth of short-size samples measured by the critical-water-level (CWL) method and that conventionally analysed for validating the nuclear data and the nuclear calculation methods has been known. The present study investigated this inconsistency in terms of a simple theoretical framework and proposed a simple and practical technique for correcting the measured sample reactivity worth without making supplementary experiments. A series of Monte Carlo calculations that simulated typical sample reactivity worth measurement by the CWL method showed that this inconsistency is effectively reduced by the present correction technique.
U for CIELO project using integral experiments of uranium-fueled FCA assembliesFukushima, Masahiro; Kitamura, Yasunori*; Yokoyama, Kenji; Iwamoto, Osamu; Nagaya, Yasunobu; Leal, L. C.*
Proceedings of International Conference on the Physics of Reactors; Unifying Theory and Experiments in the 21st Century (PHYSOR 2016) (USB Flash Drive), p.605 - 619, 2016/05
A nuclear data of U has been recently evaluated for the CIELO (Collaborative International Evaluated Library Organization) project. We tested the newly-evaluated data of U using integral experiments of the Fast Critical Assembly (FCA) performed at JAEA. We selected two integral data of uranium-fueled FCA assemblies; one is the sodium-void reactivity worth of FCA XXVII-1 assembly and the other is the criticalities of the seven assemblies of FCA IX. The benchmark tests support the evaluation done in the resonance regions. However, the U capture cross section above the unresolved resonance range needs further investigation.
Fukushima, Masahiro; Kitamura, Yasunori; Kugo, Teruhiko; Okajima, Shigeaki
Journal of Nuclear Science and Technology, 53(3), p.406 - 424, 2016/03
Times Cited Count：10 Percentile：68.36(Nuclear Science & Technology)Kitamura, Yasunori; Fukushima, Masahiro
Journal of Nuclear Science and Technology, 52(6), p.801 - 810, 2015/06
Times Cited Count：7 Percentile：51.25(Nuclear Science & Technology)Fukushima, Masahiro; Oizumi, Akito; Iwamoto, Hiroki; Kitamura, Yasunori
JAEA-Data/Code 2014-030, 50 Pages, 2015/03
JAEA-Data-Code-2014-030.pdf:10.34MB
In the IX-th experimental series in 1980's at the fast critical assembly (FCA) facility, central fission rate ratios for TRU such as 
Np, 
Pu, 
Pu, 
Am, 
Am and 
Cm to 
Pu were measured in the seven uranium-fueled assemblies with systematically changed neutron spectra. In the present report, benchmark problems with respect to central fission rate ratios were established for the assessment of the TRU's fission cross sections. We reported the sample calculation results on the benchmark problems by using JENDL-4.0.
Kitamura, Yasunori; Eguchi, Yuta
Nuclear Science and Engineering, 178(3), p.401 - 413, 2014/11
Times Cited Count：1 Percentile：8.88(Nuclear Science & Technology)Sugawara, Takanori; Oizumi, Akito; Kitamura, Yasunori; Iwamoto, Hiroki; Yagi, Takahiro*; Pyeon, C. H.*
KURRI Progress Report 2013, 1 Pages, 2014/10
The Japan Atomic Energy Agency (JAEA) has investigated the accelerator-driven system (ADS) to transmute minor actinides discharged from nuclear power plants. The ADS investigated by JAEA is a lead bismuth eutectic (LBE) cooled-tank-type ADS. It has been known that there was a major upgrade for the cross section data of lead isotopes from JENDL-3.3 to JENDL-4.0. Due to this upgrade, the value of 
of the core was significantly changed, from 0.97 calculated by JENDL-3.3 to 1.00 calculated by JENDL-4.0. The difference was mainly caused by the cross section data of the lead isotopes from JENDL-3.3 to JENDL-4.0. This study aims to measure sample worth reactivity from aluminum plates to lead or LBE ones to validate the nuclear data of lead and bismuth isotopes.
Kitamura, Yasunori; Fukushima, Masahiro
Journal of Nuclear Science and Technology, 51(6), p.752 - 765, 2014/06
Times Cited Count：7 Percentile：48.36(Nuclear Science & Technology)Kitamura, Yasunori; Fukushima, Masahiro
Journal of Nuclear Science and Technology, 51(6), p.766 - 782, 2014/06
Times Cited Count：6 Percentile：42.97(Nuclear Science & Technology)Fukushima, Masahiro; Kitamura, Yasunori; Ando, Masaki; Kugo, Teruhiko
Journal of Nuclear Science and Technology, 49(10), p.961 - 965, 2012/10
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Fukushima, Masahiro; Kitamura, Yasunori; Kugo, Teruhiko; Yamane, Tsuyoshi; Ando, Masaki; Chiba, Go; Ishikawa, Makoto; Okajima, Shigeaki
Progress in Nuclear Science and Technology (Internet), 2, p.306 - 311, 2011/10
Nishihara, Kenji; Sugawara, Takanori; Tsujimoto, Kazufumi; Kitamura, Yasunori; Pyeon, C. H.*
KURRI Progress Report 2009, P. 201, 2010/10
The regression method for pulse neutron source (PNS) experiment has been developed to monitor sub-criticality of an accelerator-driven system (ADS). This method is applicable for PNS experiment with bad experimental conditions, such as high repetition of neutron source that makes the alpha-fitting method difficult to determine delayed neutron level. In the present study, the regression method was verified using the KUCA-A core with various sub-critical levels induced by DT neutrons with several numbers of repetitions. As a result, the discrepancy of 
and count rates between experiment and the regression method was observed for the low repetitions. Further investigation for background is necessary in next study.
Fukushima, Masahiro; Kitamura, Yasunori; Kugo, Teruhiko; Yamane, Tsuyoshi; Ando, Masaki; Chiba, Go; Ishikawa, Makoto; Okajima, Shigeaki
Proceedings of Joint International Conference of 7th Supercomputing in Nuclear Application and 3rd Monte Carlo (SNA + MC 2010) (USB Flash Drive), 6 Pages, 2010/10
Sugie, Tatsuo; Hatae, Takaki; Koide, Yoshihiko; Fujita, Takaaki; Kusama, Yoshinori; Nishitani, Takeo; Isayama, Akihiko; Sato, Masayasu; Shinohara, Koji; Asakura, Nobuyuki; et al.
Fusion Science and Technology (JT-60 Special Issue), 42(2-3), p.482 - 511, 2002/09
Times Cited Count：6 Percentile：3.03(Nuclear Science & Technology)The diagnostic system of JT-60U (JT-60upgrade) is composed of about 50 individual diagnostic devices. Recently, the detailed radial profile measurements of plasma parameters have been improved, so that the internal structure of plasmas has been explored. The understanding of plasma confinement has been enhanced by density and temperature fluctuation measurements using a mm-wave reflectometer and electron cyclotron emission measurements respectively. In addition, the real-time control experiments of electron density, neutron yield, radiated power and electron temperature gradient have been carried out successfully by corresponding diagnostic devices. These measurements and the real time control contribute to improving plasma performance. Diagnostic devices for next generation fusion devices such as a CO2 laser interferometer/polarimeter and a CO2 laser collective Thomson scattering system have been developed.
Fukushima, Masahiro; Okajima, Shigeaki; Kitamura, Yasunori; Ando, Masaki; Yamane, Tsuyoshi; Mori, Takamasa; Nishi, Hiroshi; Yamane, Yoshihiro*; Kanemoto, Shigeru*
no journal, ,
no abstracts in English
Okajima, Shigeaki; Nishi, Hiroshi; Yamane, Yoshihiro*; Kanemoto, Shigeru*; Yamane, Tsuyoshi; Mori, Takamasa; Kitamura, Yasunori; Fukushima, Masahiro; Kitano, Akihiro; Ando, Masaki; et al.
no journal, ,
The program was planned and has been carried out to develop of the reactivity feedback effect measurement techniques under sub-critical condition in the start-up experiment for fast reactors. The program includes the demonstration of the developed technique in fast critical assembly (FCA) and the proposal of the appropriate measurement system based on the results. The background and the purposes of the program and the outline of development subjects are presented.
Kitamura, Yasunori; Yamane, Yoshihiro*; Okajima, Shigeaki; Fukushima, Masahiro; Ando, Masaki; Yamane, Tsuyoshi
no journal, ,
no abstracts in English
