New approach for nuclear reaction model in the combination of intra-nuclear cascade and DWBA

Hashimoto, Shintaro; Iwamoto, Osamu; Iwamoto, Yosuke; Sato, Tatsuhiko; Niita, Koji*

Nuclear Data Sheets, 118, p.258 - 261, 2014/05

https://doi.org/10.1016/j.nds.2014.04.052

Particle transport simulation codes based on the Monte Carlo technique are utilized to predict interaction of radiations with materials. The codes describe the transport of all particles, e.g. photons, electrons, nucleons, and heavy ions by various models for physical processes and nuclear reaction. In particular, nuclear reaction processes are essential parts for the accurate prediction. Recently, accelerator-based neutron sources using proton or deuteron beams with energies from 10 to 100 MeV come to be utilized for scientific and medical applications. For neutron source design, accurate description of neutron yields created by nuclear reactions is required in the simulation. However, the Intra-Nuclear Cascade type models used in most of the simulation codes are not enough to reproduce experimental data because of neglecting quantum mechanical effects. In this study, we combined the cascade type models and an event generator using the DWBA (Distorted Wave Born Approximation) calculation, which is a theoretical model based on quantum mechanics. We verified that the calculated results with the combination model can reproduce experimental data of neutron spectra in deuteron-induced reactions. We will also present the validity of the combination model for proton-induced reactions.

Measurements of neutron capture cross sections of Sn and Sn with J-PARC/MLF/ANNRI

Kimura, Atsushi; Hirose, Kentaro; Nakamura, Shoji; Harada, Hideo; Hara, Kaoru; Hori, Junichi*; Igashira, Masayuki*; Kamiyama, Takashi*; Katabuchi, Tatsuya*; Kino, Koichi*; et al.

Nuclear Data Sheets, 119, p.150 - 153, 2014/05

https://doi.org/10.1016/j.nds.2014.08.042

Surrogate reactions research at JAEA/Tokyo Tech

Chiba, Satoshi; Nishio, Katsuhisa; Makii, Hiroyuki; Aritomo, Yoshihiro*; Nishinaka, Ichiro; Ishii, Tetsuro; Tsukada, Kazuaki; Asai, Masato; Furutaka, Kazuyoshi; Hashimoto, Shintaro; et al.

Nuclear Data Sheets, 119, p.229 - 232, 2014/05

https://doi.org/10.1016/j.nds.2014.08.063

Measurements of capture rays from the neutron resonances of Se and Se at the J-PARC/MLF/ANNRI

Hori, Junichi*; Yashima, Hiroshi*; Nakamura, Shoji; Furutaka, Kazuyoshi; Hara, Kaoru; Harada, Hideo; Hirose, Kentaro; Kimura, Atsushi; Kitatani, Fumito; Koizumi, Mitsuo; et al.

Nuclear Data Sheets, 119, p.128 - 131, 2014/05

https://doi.org/10.1016/j.nds.2014.08.036

In this work, we measured the capture rays from the neutron resonances of Se and Se. A neutron time-of-flight method was adopted for the measurements with a 4 Ge spectrometer installed at the Accurate Neutron-Nucleus Reaction measurement Instrument (ANNRI) in the J-PARC Material and Life science experimental Facility (MLF). The -ray pulse-height spectra corresponding to the 27-eV resonance of Se and the 113-, 212-, 291-, 342-, 690- and 864-eV resonances of Se were obtained by gating on the TOF regions, respectively. The relative intensities of those primary transitions were derived and compared with the previous experimental data. For the 27-eV resonance of Se, a strong primary transition to the 293-keV state was observed. As for Se, the quite differences of the decay pattern were found between the resonances.

Development of anti-Compton LaBr(Ce) spectrometer for measurement of surrogate reactions

Makii, Hiroyuki; Ota, Shuya*; Ishii, Tetsuro; Nishio, Katsuhisa; Nishinaka, Ichiro; Furutaka, Kazuyoshi; Wakabayashi, Yasuo*; Chiba, Satoshi*; Igashira, Masayuki*

Nuclear Data Sheets, 119, p.361 - 364, 2014/05

https://doi.org/10.1016/j.nds.2014.08.099

Anti-Compton LaBr(Ce) spectrometers have been installed at JAEA-Tokai tandem accelerator facility in order to measure the rays from the highly excited states produced by surrogate reactions. Each spectrometer consists of a central LaBr(Ce) detector with a diameter of 10.2 cm and a length of 12.7 cm, and an annular BGO detector with a thickness of 2.5 cm and a length of 25.4 cm. In this contribution, we will present the results of performance test using the standard ray source and high-energy rays from the Al(p,)Si reaction, and a measurement plan for (n,) cross sections using a surrogate reaction at JAEA-Tokai tandem accelerator facility.

Analysis of Pu isotopes in melted fuel by neutron resonance transmission; Examination by linear absorption model

Kitatani, Fumito; Harada, Hideo; Takamine, Jun; Kureta, Masatoshi; Seya, Michio

Nuclear Data Sheets, 118, p.505 - 509, 2014/04

https://doi.org/10.1016/j.nds.2014.04.119

Feasibility study of neutron resonance transmission analysis (NRTA) has been started to quantify nuclear materials in particle-like debris of melted fuel formed in severe accidents of nuclear reactor such as Fukushima Daiichi Nuclear Power Plants. The achievable measurement accuracy was examined by NRTA using a linear absorption model for the sample in which substances other than nuclear fuel materials, such as boron, were contained. In this study, boron and iron were considered to be contained in spent nuclear fuel as impurities. The neutron flight path is 5 m, that is the length between the neutron source and a neutron detector. Neutron absorption spectra were calculated using the total neutron absorption cross-section by JENDL-4.0. The absorption spectra together with their errors were evaluated. The achievable accuracy of Pu isotopic density was deduced as a function of neutron intensity and impurity density. This research was supported by JSGO/MEXT.

R-matrix analysis for n + O cross-sections up to E = 6.0 MeV with covariances

Kunieda, Satoshi; Kawano, Toshihiko*; Paris, M.*; Hale, G. M.*; Shibata, Keiichi; Fukahori, Tokio

Nuclear Data Sheets, 118, p.250 - 253, 2014/04

https://doi.org/10.1016/j.nds.2014.04.050

Oxygen is one of the most important materials in nuclear applications. However, there are big discrepancies among experimental and evaluated data in O() cross section. Also, there are increasing demands for giving uncertainties in evaluated cross section to estimate the margin of integral calculations. We analyzed experimental cross sections with R-matrix theory, and estimated cross sections with their uncertainties. In this analysis, not only the neutron but also an inverse reactions were included. The systematic uncertainties were also considered for each measurement. The resulting cross sections and uncertainties mirror both experimental and theoretical knowledges.

Remarks on KERMA factors in ACE files

Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Sato, Satoshi

Nuclear Data Sheets, 118, p.450 - 452, 2014/04

https://doi.org/10.1016/j.nds.2014.04.103

KERMA (Kinematic Energy Release in Material) factors are used as response data in order to obtain nuclear heating in nuclear analyses. These data are not directly included in nuclear data libraries and they in ACE (A Compact ENDF) files for the Monet Carlo radiation transport code MCNP are deduced from cross section data for all the reactions in nuclear data libraries with the NJOY code. Many peoples use these data unquestioningly, but little is known concerning fact that most of these data are not always correct. Thus we have examined KERMA factors in the latest official ACE files; those of JENDL-4.0, ENDF/B-VII.1, JEFF-3.1.1, etc. It is found out that a lot of KERMA data in the official ACE files of JENDL-4.0, ENDF/B-VII.1, JEFF-3.1.1 are not always correct.

Sensitivity and uncertainty analysis for a minor-actinide transmuter with JENDL-4.0

Iwamoto, Hiroki; Nishihara, Kenji; Sugawara, Takanori; Tsujimoto, Kazufumi

Nuclear Data Sheets, 118, p.519 - 522, 2014/04

https://doi.org/10.1016/j.nds.2014.04.123

The CIELO Collaboration; Neutron reactions on H, O, Fe, U, and Pu

Chadwick, M. B.*; Dupont, E.*; Bauge, E.*; Blokhin, A.*; Bouland, O.*; Brown, D. A.*; Capote, R.*; Carlson, A. D.*; Danon, Y.*; De Saint Jean, C.*; et al.

Nuclear Data Sheets, 118, p.1 - 25, 2014/04

https://doi.org/10.1016/j.nds.2014.04.002

CIELO (Collaborative International Evaluated Library Organization) provides a new working paradigm to facilitate evaluated nuclear reaction data advances. It brings together experts from across the international nuclear reaction data community to identify and document discrepancies among existing evaluated data libraries, measured data, and model calculation interpretations, and aims to make progress in reconciling these discrepancies to create more accurate ENDF-formatted files. The focus will initially be on a small number of the highest-priority isotopes, namely H, O, Fe, U, and Pu. This paper identifies discrepancies between various evaluations of the highest priority isotopes. The evaluated data for these materials in the existing nuclear data libraries are reviewed, and some integral properties are given. The paper summarizes a program of nuclear science and computational work needed to create the new CIELO nuclear data evaluations.