Harada, Hideo; Takayama, Naoki; Komeda, Masao
Journal of Physics Communications (Internet), 4(8), p.085004_1 - 085004_17, 2020/08
A new convention of epithermal neutron spectrum is formulated for improving accuracy of resonance integrals. The new type function is proposed as an approximating function of epithermal neutron spectrum based on calculations by the state-of-art Monte Carlo code MVP-3. Bias effects on determination of resonance integrals due to utilizing approximating functions of the traditional types and the new type are compared. The other bias effect is also investigated, which is caused by neglecting position dependence of a neutron spectrum inside an irradiation capsule. For demonstrating the bias effects due to these assumptions on neutron spectrum quantitatively in a practical case, the thermal neutron-capture cross section and resonance integral of Cs measured at a research reactor JRR-3 are re-evaluated. A superior property of the proposed new convention is discussed. The experimental method is proposed to determine the new shape factor introduced in the convention by a combinational use of triple flux monitors (Au, Co and Zr), and its analytical methodology is formulated.
Ma, F.; Kopecky, S.*; Alaerts, G.*; Harada, Hideo; Heyse, J.*; Kitatani, Fumito; Noguere, G.*; Paradela, C.*; alamon, L.*; Schillebeeckx, P.*; et al.
Journal of Analytical Atomic Spectrometry, 35(3), p.478 - 488, 2020/03
Tsuchiya, Harufumi; Koizumi, Mitsuo; Kitatani, Fumito; Harada, Hideo
Nuclear Instruments and Methods in Physics Research A, 932, p.16 - 26, 2019/07
Kimura, Atsushi; Nakamura, Shoji; Terada, Kazushi*; Nakao, Taro*; Mizuyama, Kazuhito*; Iwamoto, Nobuyuki; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; et al.
Journal of Nuclear Science and Technology, 56(6), p.479 - 492, 2019/06
Hagiwara, Kaito*; Yano, Takatomi*; Das, P. K.*; Lorenz, S.*; Ou, Iwa*; Sakuda, Makoto*; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Nobuyuki; Harada, Hideo; et al.
Progress of Theoretical and Experimental Physics (Internet), 2019(2), p.023D01_1 - 023D01_26, 2019/02
Mastromarco, M.*; Manna, A.*; Aberle, O.*; Andrzejewski, J.*; Harada, Hideo; Kimura, Atsushi; n_TOF Collaboration*; 116 of others*
European Physical Journal A, 55(1), p.9_1 - 9_20, 2019/01
Nakamura, Shoji; Terada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Iwamoto, Osamu; Harada, Hideo; Uehara, Akihiro*; Takamiya, Koichi*; Fujii, Toshiyuki*
Journal of Nuclear Science and Technology, 56(1), p.123 - 129, 2019/01
Accurate data of -ray emission probabilities are frequently needed when one quantitatively determines the amount of isotope by -ray measurements or obtains neutron capture cross-sections using them. Americium-243, one of the most important minor actinides, produces Am after neutron capture. The 744-keV -ray decaying from the ground state of Am has a relatively large -ray emission probability c.a. 66%, however, its uncertainty is as large as 29%. The uncertainty of the -ray emission probability leads to a major factor of the systematic uncertainty on determining an amount of isotope, and therefore the -ray emission probability was measured by using an activation method and an examined level structure of Cm. In this study, the emission probability of 744-keV ray was derived as 66.51.1%, and its uncertainty was improved from 29% to 2%.
Terada, Kazushi*; Kimura, Atsushi; Nakao, Taro*; Nakamura, Shoji; Mizuyama, Kazuhito*; Iwamoto, Nobuyuki; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; et al.
Journal of Nuclear Science and Technology, 55(10), p.1198 - 1211, 2018/10
Damone, L.*; Barbagallo, M.*; Mastromarco, M.*; Cosentino, L.*; Harada, Hideo; Kimura, Atsushi; n_TOF Collaboration*; 152 of others*
Physical Review Letters, 121(4), p.042701_1 - 042701_7, 2018/07
erovnik, G.*; Schillebeeckx, P.*; Becker, B.*; Fiorito, L.*; Harada, Hideo; Kopecky, S.*; Radulovic, V.*; Sano, Tadafumi*
Nuclear Instruments and Methods in Physics Research A, 877, p.300 - 313, 2018/01
Methodologies to derive cross section data from spectrum integrated reaction rates were studied. The Westcott convention and some of its approximations were considered. The accuracy of the results strongly depends on the assumptions that are made about the neutron energy distribution, which is mostly parameterised as a sum of a thermal and an epi-thermal component. Resonance integrals derived from such data can be strongly biased. When the energy dependence of the cross section is known and information about the neutron energy distribution is available, a method to correct for a bias on the cross section at thermal energy is proposed. Reactor activation measurements to determine the thermal Am(n, ) cross section reported in the literature were reviewed, where the results were corrected to account for possible biases. These data combined with results of time-of-flight measurements give a capture cross section 720 (14) b for Am(n, ) at thermal energy.
Kimura, Atsushi; Harada, Hideo; Kunieda, Satoshi; Katabuchi, Tatsuya*
Nippon Genshiryoku Gakkai-Shi, 59(11), p.654 - 658, 2017/11
no abstracts in English
Terada, Kazushi; Nakao, Taro; Nakamura, Shoji; Kimura, Atsushi; Iwamoto, Osamu; Harada, Hideo; Takamiya, Koichi*; Hori, Junichi*
EPJ Web of Conferences, 146, p.03019_1 - 03019_4, 2017/09
The research project entitled "Research and development for Accuracy Improvement of neutron nuclear data on Minor ACtinides (AIMAC)" has been started to improve the reliability of the neutron cross section date of MAs. In order to obtain accurate cross section data, it is indispensable to determine the amount of MA sample accurately and non-destructively. However, the uncertainty concerning the amount of sample is not assured in some cases. Therefore, as a part of the AIMAC project, this study is aimed to development the technique for accurate determination of the amount of samples by two different methods: -ray spectroscopic method and calorimetric method. This contribution presents the developed techniques together with results obtained by two independent techniques.
Kimura, Atsushi; Harada, Hideo; Nakamura, Shoji; Toh, Yosuke; Igashira, Masayuki*; Katabuchi, Tatsuya*; Mizumoto, Motoharu*; Hori, Junichi*
EPJ Web of Conferences, 146, p.11031_1 - 11031_4, 2017/09
Nakao, Taro; Terada, Kazushi; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; Hori, Junichi*
EPJ Web of Conferences, 146, p.03021_1 - 03021_4, 2017/09
A new data acquisition system (DAQ system) in J-PARC Materials and Life Science Experimental Facility (MLF) ANNRI was developed. Increasing beam power of MLF in recent years allows beam line users to obtain high quantity experimental data yields. Compared to 2008, more than 20 times beam current is achieved in 2015. For the purpose to correspond strong beam power of MLF, a new DAQ system for the array of the Ge detectors in ANNRI is developed. The DAQ system is also going to be used for processing signals from a Li glass detector, which is under development at ANNRI for measurement of total neutron cross sections. Commissioning experiment of a new DAQ system at ANNRI was performed by using 0.1mmt Au sample with 500kW J-PARC proton beam power. An applicability of time-of-flight method for both neutron capture and total cross-sections measurements was checked. ADC and TDC nonlinearity, energy resolution, multi-channel coincidence and dead time performance for the array of the Ge detectors were also evaluated. The dead time value for Ge detectors was successfully decreased to 1/4 from the previous DAQ system with minor deterioration on energy resolution. The author would like to thank the accelerator and technical staff at J-PARC for operation of the accelerator and the neutron production target and for the other experimental supports. Present study includes the result of "Research and Development for accuracy improvement of neutron nuclear data on minor actinides" entrusted to the Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).
Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kimura, Atsushi; Terada, Kazushi; Nakao, Taro; Nakamura, Shoji; Mizuyama, Kazuhito; Igashira, Masayuki*; Katabuchi, Tatsuya*; et al.
EPJ Web of Conferences, 146, p.11001_1 - 11001_6, 2017/09
erovnik, G.*; Schillebeeckx, P.*; Cano-Ott, D.*; Jandel, M.*; Hori, Junichi*; Kimura, Atsushi; Rossbach, M.*; Letourneau, A.*; Noguere, G.*; Leconte, P.*; et al.
EPJ Web of Conferences, 146, p.11035_1 - 11035_4, 2017/09
Sano, Tadafumi*; Hori, Junichi*; Takahashi, Yoshiyuki*; Yashima, Hiroshi*; Lee, J.*; Harada, Hideo
EPJ Web of Conferences, 146, p.03031_1 - 03031_3, 2017/09
Shibahara, Yuji*; Hori, Junichi*; Takamiya, Koichi*; Fujii, Toshiyuki*; Fukutani, Satoshi*; Sano, Tadafumi*; Harada, Hideo
EPJ Web of Conferences, 146, p.03028_1 - 03028_4, 2017/09
Paradela, C.*; Heyse, J.*; Kopecky, S.*; Schillebeeckx, P.*; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi
EPJ Web of Conferences, 146, p.09002_1 - 09002_4, 2017/09
Chen, Y. H.*; Tassan-Got, L.*; Harada, Hideo; Kimura, Atsushi; n_TOF Collaboration*; 130 of others*
EPJ Web of Conferences, 146, p.03020_1 - 03020_4, 2017/09
The experimental area 2 (EAR-2) at CERNs neutron time-of-flight facility (n_TOF), which is operational since 2014, is designed and built as a short-distance complement to the experimental area 1 (EAR-1). The Parallel Plate Avalanche Counter (PPAC) monitor experiment was performed to characterize the beam profile and the shape of the neutron flux at EAR-2. The prompt -flash which is used for calibrating the time-of-flight at EAR-1 is not seen by PPAC at EAR-2, shedding light on the physical origin of this -flash.