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Journal Articles

Integral experiments of technetium-99 using fast-neutron source reactor "YAYOI"

Nakamura, Shoji; Hatsukawa, Yuichi*; Kimura, Atsushi; Toh, Yosuke; Harada, Hideo

Journal of Nuclear Science and Technology, 58(12), p.1318 - 1329, 2021/12

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

The present study performed fast-neutron capture cross-section measurement of $$^{99}$$Tc by an activation method using a fast-neutron source reactor "YAYOI" of the University of Tokyo. Technetium-99 samples were irradiated with reactor neutrons using a pneumatic system. Reaction rates of $$^{99}$$Tc were obtained by measuring decay gamma rays emitted from $$^{100}$$Tc. The neutron flux at an irradiation position was monitored with gold foils. The fast-neutron capture cross section of $$^{99}$$Tc at neutron energy of 85 keV was derived as 0.432$$pm$$0.023 barn by using the reaction rates of $$^{99}$$Tc, evaluated cross-section data and the fast-neutron flux spectrum of the YAYOI reactor. The present study agreed with the evaluated nuclear data library JENDL-4.0.

Journal Articles

Bias effects on g- and s-factors in Westcott convention

Harada, Hideo

Applied Sciences (Internet), 11(14), p.6558_1 - 6558_20, 2021/07

 Times Cited Count:0 Percentile:0(Chemistry, Multidisciplinary)

For accuracy improvement of neutron activation analysis and neutron capture cross section, bias effects are investigated on g- and s-factors in the Westcott convention. As origins of biases, a joining function shape, neutron temperature and sample temperature, have been investigated. Biases are quantitatively deduced for two 1/v isotopes ($$^{197}$$Au, $$^{59}$$Co) and six non-1/v isotopes ($$^{241}$$Am, $$^{151}$$Eu, $$^{103}$$Rh, $$^{115}$$In, $$^{177}$$Hf, $$^{226}$$Ra). The s-factor calculated with a joining function deduced recently by a detailed Monte Carlo simulation is compared to s-factors calculated with traditional joining functions by Westcott. The results show the bias induced by sample temperature is small as the order of 0.1% for g-factor and the order of 1% for s-factor. On the other hand, biases induced by a joining function shape for s-factor depend significantly on both isotopes and neutron temperature. As the result, reaction rates are also affected significantly as well. The bias size on reaction rate is given in the case of epithermal neutron index r = 0.1, for the eight isotopes.

Journal Articles

Neutron capture cross sections of curium isotopes measured with ANNRI at J-PARC

Kawase, Shoichiro*; Kimura, Atsushi; Harada, Hideo; Iwamoto, Nobuyuki; Iwamoto, Osamu; Nakamura, Shoji; Segawa, Mariko; Toh, Yosuke

Journal of Nuclear Science and Technology, 58(7), p.764 - 786, 2021/07

 Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)

Journal Articles

Tackling discrepancy of data; Looking back at international cooperation on data evaluation

Harada, Hideo

Kaku Deta Nyusu (Internet), (129), p.35 - 43, 2021/06

This paper explained the activities of the International Nuclear Data Evaluation Co-operation (WPEC)'s subgroup SG-41, which was carried out to improve the accuracy of nuclear data. In this paper, by focusing on how to deal with discrepant data, the method of deriving recommended values from multiple measurement results was reviewed. It also explained how to derive the recommended values, including exercises.

Journal Articles

High-spin states in $$^{35}$$S

Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Aoi, Nori*; Azaiez, F.*; Furutaka, Kazuyoshi; Hatsukawa, Yuichi; Kimura, Atsushi; Kisamori, Keiichi*; Kobayashi, Motoki*; et al.

Physical Review C, 103(3), p.034327_1 - 034327_8, 2021/03

 Times Cited Count:0 Percentile:0.03(Physics, Nuclear)

Journal Articles

HPRL; International cooperation to identify and monitor priority nuclear data needs for nuclear applications

Dupont, E.*; Bossant, M.*; Capote, R.*; Carlson, A. D.*; Danon, Y.*; Fleming, M.*; Ge, Z.*; Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; et al.

EPJ Web of Conferences, 239, p.15005_1 - 15005_4, 2020/09

 Times Cited Count:0 Percentile:0.19

Journal Articles

Overview of the OECD-NEA Working Party on International Nuclear Data Evaluation Cooperation (WPEC)

Fleming, M.*; Bernard, D.*; Brown, D.*; Chadwick, M. B.*; De Saint Jean, C.*; Dupont, E.*; Ge, Z.*; Harada, Hideo; Hawari, A.*; Herman, M.*; et al.

EPJ Web of Conferences, 239, p.15002_1 - 15002_4, 2020/09

 Times Cited Count:0 Percentile:0.19

Journal Articles

A New convention for the epithermal neutron spectrum for improving accuracy of resonance integrals

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 $$^{135}$$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 $$beta$$ introduced in the convention by a combinational use of triple flux monitors ($$^{197}$$Au, $$^{59}$$Co and $$^{94}$$Zr), and its analytical methodology is formulated.

Journal Articles

Non-destructive analysis of samples with a complex geometry by NRTA

Ma, F.; Kopecky, S.*; Alaerts, G.*; Harada, Hideo; Heyse, J.*; Kitatani, Fumito; Noguere, G.*; Paradela, C.*; $v{S}$alamon, L.*; Schillebeeckx, P.*; et al.

Journal of Analytical Atomic Spectrometry, 35(3), p.478 - 488, 2020/03

AA2019-0356.pdf:2.54MB

 Times Cited Count:1 Percentile:34.45(Chemistry, Analytical)

Journal Articles

Performance of large volume LaBr$$_{3}$$ scintillation detector equipped with specially-designed shield for neutron resonance capture analysis

Tsuchiya, Harufumi; Koizumi, Mitsuo; Kitatani, Fumito; Harada, Hideo

Nuclear Instruments and Methods in Physics Research A, 932, p.16 - 26, 2019/07

 Times Cited Count:0 Percentile:0.02(Instruments & Instrumentation)

Journal Articles

Measurements of the $$^{243}$$Am neutron capture and total cross sections with ANNRI at J-PARC

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

 Times Cited Count:5 Percentile:75.46(Nuclear Science & Technology)

Journal Articles

Gamma-ray spectrum from thermal neutron capture on gadolinium-157

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

 Times Cited Count:14 Percentile:82.27(Physics, Multidisciplinary)

Journal Articles

Cross section measurements of $$^{155,157}$$Gd(n,$$gamma$$) induced by thermal and epithermal neutrons

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

 Times Cited Count:14 Percentile:93.24(Physics, Nuclear)

Journal Articles

Measurements of gamma-ray emission probabilities in the decay of americium-244g

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

 Times Cited Count:1 Percentile:23.13(Nuclear Science & Technology)

Accurate data of $$gamma$$-ray emission probabilities are frequently needed when one quantitatively determines the amount of isotope by $$gamma$$-ray measurements or obtains neutron capture cross-sections using them. Americium-243, one of the most important minor actinides, produces $$^{244}$$Am after neutron capture. The 744-keV $$gamma$$-ray decaying from the ground state of $$^{244}$$Am has a relatively large $$gamma$$-ray emission probability c.a. 66%, however, its uncertainty is as large as 29%. The uncertainty of the $$gamma$$-ray emission probability leads to a major factor of the systematic uncertainty on determining an amount of isotope, and therefore the $$gamma$$-ray emission probability was measured by using an activation method and an examined level structure of $$^{244}$$Cm. In this study, the emission probability of 744-keV $$gamma$$ ray was derived as 66.5$$pm$$1.1%, and its uncertainty was improved from 29% to 2%.

Journal Articles

Measurements of neutron total and capture cross sections of $$^{241}$$Am with ANNRI at J-PARC

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

 Times Cited Count:10 Percentile:87.34(Nuclear Science & Technology)

Journal Articles

$$^7$$Be(n,p)$$^7$$Li reaction and the cosmological lithium problem; Measurement of the cross section in a wide energy range at n_TOF at CERN

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

 Times Cited Count:33 Percentile:93.14(Physics, Multidisciplinary)

Journal Articles

Systematic effects on cross section data derived from reaction rates in reactor spectra and a re-analysis of $$^{241}$$Am reactor activation measurements

$v{Z}$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

 Times Cited Count:3 Percentile:45.99(Instruments & Instrumentation)

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 $$^{241}$$Am(n, $$gamma$$) 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 $$^{241}$$Am(n, $$gamma$$) at thermal energy.

Journal Articles

Cutting-edge studies on nuclear data for continuous and emerging need, 2; Nuclear data measurements and theoretical analysis in the resonance region

Kimura, Atsushi; Harada, Hideo; Kunieda, Satoshi; Katabuchi, Tatsuya*

Nihon Genshiryoku Gakkai-Shi ATOMO$$Sigma$$, 59(11), p.654 - 658, 2017/11

no abstracts in English

Journal Articles

Technical developments for accurate determination of amount of samples used for TOF measurements

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

 Times Cited Count:2 Percentile:85.61

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: $$gamma$$-ray spectroscopic method and calorimetric method. This contribution presents the developed techniques together with results obtained by two independent techniques.

Journal Articles

Neutron capture cross section measurements of $$^{120}$$Sn, $$^{122}$$Sn and $$^{124}$$Sn with the array of Ge spectrometer at the J-PARC/MLF/ANNRI

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

 Times Cited Count:0 Percentile:0.08

490 (Records 1-20 displayed on this page)