Okumura, Keisuke; Sugino, Kazuteru; Chiba, Go; Nagaya, Yasunobu; Yokoyama, Kenji; Kugo, Teruhiko; Ishikawa, Makoto; Okajima, Shigeaki
Journal of the Korean Physical Society, 59(2), p.1135 - 1140, 2011/08
The new version of Japanese evaluated nuclear data library, JENDL-4.0, is tested with integral data of fission systems. This data testing is carried out with a wide range of integral data including the critical benchmarks preserved in the International Handbook of Evaluated Criticality Safety Benchmark Experiments, the experimental data of MOX-fueled critical assemblies relating to the plutonium aging effect, the critical data of various fast critical assemblies and the fast reactors JOYO and MONJU, and the post-irradiation examination data of the pressurized-water reactor Takahama-3 and the fast reactor JOYO. The benchmark calculations are performed with a continuous-energy Monte Carlo code MVP-II or a sophisticated deterministic neutron transport code system. Benchmark calculations with other libraries, such as JENDL-3.3, ENDF/B-VII.0 and JEFF-3.1, are also performed, and differences in performance of these libraries are discussed with a help of sensitivity profiles to nuclear data.
Iwamoto, Yosuke; Satoh, Daiki; Nakane, Yoshihiro; Nakashima, Hiroshi; Endo, Akira; Sakamoto, Yukio; Hagiwara, Masayuki*; Iwase, Hiroshi*; Yashima, Hiroshi*; Tamii, Atsushi*; et al.
Journal of the Korean Physical Society, 59(2), p.1753 - 1756, 2011/08
Neutron production cross sections of carbon and iron targets for 140 MeV proton at 180 were measured at the RCNP cyclotron facility. The neutron energy spectra were obtained by using the time-of-flight technique in the energy range above 1 MeV. The results of carbon and iron targets were compared with experimental data for 113 MeV (p,xn) reactions at 150 deg by Meier et al. Our data gave good agreements with them in spite of different incident energies and angles. Calculations were performed with different intranuclear cascade models (Bertini, ISOBAR, and JQMD) implemented in the PHITS code. Calculated results with the ISOBAR and JQMD models roughly agreed with the experimental data for iron targets, although Bertini could not reproduce the high energy neutrons above 10 MeV.
Satoh, Daiki; Moriguchi, Daisuke*; Kajimoto, Tsuyoshi*; Koba, Yusuke*; Nakamura, Yasuhiro*; Shigyo, Nobuhiro*; Ueyama, Masahiko*; Uozumi, Yusuke*; Yoshioka, Masakatsu*; Matsufuji, Naruhiro*; et al.
Journal of the Korean Physical Society, 59(2), p.1741 - 1744, 2011/08
The data of neutron production from heavy-ion interactions are of great importance for the dose assessment in heavy-ion therapy. We have already evaluated the data of neutron production for thick targets, in which the incident heavy ions completely stop, by the measurements and the reevaluation of the existing data reported by Kurosawa et al. As a next step of the research, we plan to evaluate the neutron-production cross-section data for thin targets. These data are useful to understand the mechanism of heavy-ion interaction, and improve the reaction model in particle transport codes. The previously reported cross-section data by Iwata et al. were revised by using a new set of neutron-detection efficiency values calculated with SCINFUL-QMD code. While the original data gave the larger values than the predictions of particle transport codes above 200 MeV due to the underestimation of the efficiencies, it was improved by this revision. In addition, we have started the new cross-section measurements at HIMAC. All the data of neutron-production cross sections were compared with the predictions of particle transport codes.
Shibata, Keiichi; Iwamoto, Osamu; Nakagawa, Tsuneo; Iwamoto, Nobuyuki; Ichihara, Akira; Kunieda, Satoshi; Chiba, Satoshi; Katakura, Junichi; Otsuka, Naohiko*
Journal of the Korean Physical Society, 59(2), p.1046 - 1051, 2011/08
In JENDL-4, much emphasis is placed on the improvements of FP and MA data. For achieving this, new nuclear model codes POD and CCONE were developed, since experimental data are very scarce for those nuclei. The global coupled-channel optical model parameters, which were obtained in the wide mass region, were used for the evaluation of cross sections. Thermal cross sections of actinides were determined by carefully examining available experimental data. Special care was taken for the resonance region of U in order to reproduce measured criticalities and Na-void reactivities for U fueled fast-neutron cores. As for FP, resolved resonance parameters were updated for more than 100 nuclei. The cross sections of above the resonance region were evaluated by using the POD and CCONE codes. Fission product yield data were obtained from the ENDF/B-VII.0 data with some modifications. The new library, which contains neutron data for 406 nuclei, will be made available in 2010.
Journal of the Korean Physical Society, 59(2), p.963 - 966, 2011/08
The nuclear data evaluation was performed to develop the Japanese Evaluated Nuclear Data Library, JENDL-4.0, which was released on early 2010. The evaluation of fission products (e.g., Nd-Dy of lanthanoid elements) in the smooth region up to 20MeV was carried out by dividing the procedure into two parts. First, the coupled-channels optical model calculations were done to obtain the neutron transmission coefficients for target nuclides. Second, the reaction cross sections were calculated by using nuclear reaction model. The reaction cross sections for total, elastic, and inelastic scattering cross sections, and the other reaction cross sections whose channels are open were evaluated to reproduce measured cross sections. It is found that the presently obtained reaction cross sections, angular distributions and double differential cross sections of emitted particles and photons were well consistent with experimental data.
Iwamoto, Osamu; Nakagawa, Tsuneo; Chiba, Satoshi; Otsuka, Naohiko*
Journal of the Korean Physical Society, 59(2), p.1224 - 1229, 2011/08
Covariances of nuclear data in JENDL-4 have been evaluated. The covariance evaluations are basically based on available experimental data. The fission cross sections for 6 major actinides of U and Pu were evaluated simultaneously using experimental data of both cross sections and their ratios. The deduced covariance has correlations between the data of different nuclei. For minor actinide, covariances of the fission cross sections were obtained from evaluation using GMA code. For other many reaction cross sections, theoretical calculations with CCONE code were performed for cross section evaluations. The covariances were estimated using KALMAN code with sensitivities against model parameters. For resonance parameters and average number of fission neutrons, covariances were also evaluated.
Kunieda, Satoshi; Fukahori, Tokio; Hirayama, Shusuke*; Watanabe, Yukinobu*
Journal of the Korean Physical Society, 59(2), p.911 - 914, 2011/08
Applicability of the pre-equilibrium coalescence model was investigated toward advanced nuclear data. This study was devoted to the analysis for nucleon-induced alpha-particle production cross sections up to 200 MeV. The optical model calculation was performed with suitable potential parameters both for incident- and outgoing- channels. The Iwamoto-Harada-Sato coalescence model was tentatively incorporated into the GNASH code in order to take account the pickup contribution from the pre-equilibrium stages. It was found that the present approach can reproduce measured cross sections better than empirical models which had been commonly used for nuclear data evaluations up to 100 MeV. From comparisons between the model calculations and measurements, we discuss the behaviors of the model parameters and applicability limit of the present approach.
Kin, Tadahiro; Furutaka, Kazuyoshi; Goko, Shinji*; Harada, Hideo; Kimura, Atsushi; Kitatani, Fumito; Nakamura, Shoji; Ota, Masayuki*; Oshima, Masumi; Toh, Yosuke; et al.
Journal of the Korean Physical Society, 59(2), p.1769 - 1772, 2011/08
For the developments of advanced reactors such as fast breeder reactors or accelerator driven systems, nuclear data of minor actinides (MAs) and long-lived fission products (LLFPs) are important. However, these data are insufficient at present in quantity and quality. To overcome/improve such a situation, we have developed a 4 germanium spectrometer to measure neutron capture cross sections of MAs and LLFPs by the time-of-flight (TOF) method. The spectrometer was installed in the MLF in the J-PARC. At the conference, we will report a result of a measurement of the neutron capture cross section for gold by the TOF method to develop an analysis method. The analysis methods will be used for MAs and LLFPs. During the experiment for gold, the accelerator of J-PARC was operated in so called "double-bunch mode". In the mode, protons injected to the Japan Spallation Neutron Source (JSNS) have a time structure. The time structure affects TOF measurements. Mainly the accelerator is operated in the mode, it is important to know the effect. We found dead-time effect can be corrected by using a random-pulse generator. Background components can be removed with results of measurements of a blank sample. The cross section measured was normalized by the value in ENDF B/VII at the thermal energy. Finally, the cross section of gold in the incident neutron energy range from the thermal to 10 keV was obtained. Because the result is in good agreement with ENDF B/VII, we found the analysis method can be applied for experimental data obtained with the spectrometer.
Onishi, Seiki; Kondo, Keitaro; Sato, Satoshi; Ochiai, Kentaro; Takakura, Kosuke; Konno, Chikara; Murata, Isao*
Journal of the Korean Physical Society, 59(2), p.1949 - 1952, 2011/08
So far we carried out many integral benchmark experiments (in-situ experiments and Time-Of-Flight experiments) for nuclear data with DT neutrons at the Fusion Neutronics Source facility in Japan Atomic Energy Agency. In addition to those, we have a plan to perform new integral benchmark experiments for nuclear data with a DT neutron beam, which can investigate nuclear data for almost the whole angle and the whole energy. Because the large-size tritium target in FNS is difficult to procure, we have started to build a new DT neutron beam with the small tritium target, which is easy to obtain, at the first target room of FNS. We already designed a collimator system for the DT neutron beam based on calculations. In this work, under that design, the collimator was constructed. Then the characteristics of the neutron field were measured in order to confirm the DT neutron beam performance. It was demonstrated that the DT neutron beam was realized as calculated.
Ochiai, Kentaro; Kondo, Keitaro; Onishi, Seiki; Takakura, Kosuke; Sato, Satoshi; Abe, Yuichi; Konno, Chikara; Suzuki, Chihiro*; Yagi, Takahiro*
Journal of the Korean Physical Society, 59(2), p.1953 - 1956, 2011/08
Lead is an important candidate material as multiplier of nuclear fusion reactor. Few DT neutron integral benchmark experiments were performed for lead so far. Therefore, we have carried out an integral benchmark experiment on lead at the DT neutron source facility of JAEA, FNS. A cubic lead assembly on a side of 45.3 cm was set up and was irradiated with the DT neutron source. Reaction rates of the Al(n,)Na, Nb(n,2n)Nb, Zr(n,2n)Zr and In(n,n')In reactions were measured as fast neutron spectrum indices in the assembly. A small NE213 spectrometer was also used for measurement of neutron spectra in the assembly. A Monte Carlo calculation code, MCNP5, was adopted to calculate the above neutron spectra and activation reaction rates. Nuclear data libraries, JENDL-3.3, ENDF/B-VII.0, JEFF-3.1 and FENDL-2.1, were used in the calculation. The calculation results of the three libraries except for JENDL-3.3 agreed with the measuring ones. In case of JENDL-3.3, some remarkable disagreements were found. From our investigations, it was pointed out that the inappropriate evaluation of the (n,2n) and inelastic cross sections of lead in JENDL-3.3 caused such disagreement.
Nakamura, Shoji; Furutaka, Kazuyoshi; Goko, Shinji; Harada, Hideo; Kimura, Atsushi; Kin, Tadahiro; Kitatani, Fumito; Koizumi, Mitsuo; Ota, Masayuki; Oshima, Masumi; et al.
Journal of the Korean Physical Society, 59(2), p.1773 - 1776, 2011/08
A series of neutron-capture cross-section measurements using the time-of flight method has been started at the J-PARC/MLF/ANNRI. As a part of the measurements, we have measured the neutron-capture cross-sections of Pd isotopes such as Pd.
Kitatani, Fumito; Harada, Hideo; Goko, Shinji*; Utsunomiya, Hiroaki*; Akimune, Hidetoshi*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*
Journal of the Korean Physical Society, 59(2), p.1836 - 1839, 2011/08
The photo-nuclear cross section of Se isotopes (Se, Se, Se, Se) were measured with laser-Compton scattering (LCS) -rays to supply fundamental data for the estimation of the inverse reaction cross sections, i.e., the Se(,) Se cross section. An enriched Se isotope samples were irradiated with LCS -rays whose maximum energy was varied from each near neutron separation energy to 16.0 MeV. The energy distributions of LCS -rays were precisely determined using a high-resolution high-energy photon spectrometer (HHS). Emitted neutrons were detected by a high efficiency 4-He detector. The excitation function of the photo-nuclear cross section of Se isotopes were determined for the energy range form each near neutron separation energy to near 16.0 MeV. The energy point corresponding to each cross section was deduced using the accurately determined energy distribution of LCS -rays.
Harada, Hideo; Goko, Shinji*; Kimura, Atsushi; Ota, Masayuki*; Oshima, Masumi; Kitatani, Fumito; Toh, Yosuke; Furutaka, Kazuyoshi; Kin, Tadahiro; Koizumi, Mitsuo; et al.
Journal of the Korean Physical Society, 59(2), p.1547 - 1552, 2011/08
For the improvement of the accuracy on the neutron capture cross sections, a 4 Ge spectrometer was developed. The 4 Ge spectrometer is a unique tool due to its superior energy resolution for studying properties on neutron capture reactions, not only capture cross sections but also resonance identification, -ray intensity distribution, and spin-parity assignment. For example, its performance on the resonance identification was demonstrated using a Ag sample. On the measurement of a -ray intensity distribution for each resonance, the results of U will be shown. Using the 4 Ge spectrometer, the measurements of neutron capture cross sections were started at the J-PARC/MLF/ANNRI. The preliminary results on the measurements of neutron capture cross sections will be discussed mainly based on measurements of neutron capture cross sections for Am, together with related techniques.
Kimura, Atsushi; Furutaka, Kazuyoshi; Goko, Shinji*; Harada, Hideo; Kin, Tadahiro; Kitatani, Fumito; Koizumi, Mitsuo; Nakamura, Shoji; Ota, Masayuki*; Oshima, Masumi; et al.
Journal of the Korean Physical Society, 59(2), p.1828 - 1831, 2011/08
Konno, Chikara; Ochiai, Kentaro; Onishi, Seiki
Journal of the Korean Physical Society, 59(2), p.1092 - 1095, 2011/08
JSSTDL-300 is a multigroup library for shielding applications produced from JENDL-3.2. The self-shielding correction in JSSTDL-300 is probably inadequate due to the following two reasons, (1) the weighting function of Legendre order = 0 is applied for all Legendre orders, (2) the f-table of the scattering matrix is the same as that of the elastic scattering. Thus we examined the effects of these problems through a simple benchmark test, the model of which consisted of an aluminum, iron, nickel or copper sphere of 1 m in radius with a 20 MeV neutron source in the center. Neutron spectra in the sphere were calculated with ANISN and were compared with those obtained with MCNP4C. It was found out that the effects were different dependent to materials and were the largest for copper. Adequate f-table and weighting function should be adopted in generation of multigroup libraries.
Hara, Kaoru; Kin, Tadahiro; Oshima, Masumi; Nakamura, Shoji; Kimura, Atsushi; Koizumi, Mitsuo; Toh, Yosuke
Journal of the Korean Physical Society, 59(2), p.1832 - 1835, 2011/08
We studied a decay scheme in the Ge(,)Ge reaction. It is essential information for accurate determination of the neutron capture cross section of Ge with the prompt -ray detection method, when the cross section is derived by summing all the intensities of ground-state or primary transitions. However, the decay from/to Ge-state above 2 MeV is unknown, where the neutron separation energy is 6.5 MeV. The - coincidence experiments were performed at the cold neutron beam line of the Japan Research Reactor of JAEA. The multiple prompt -rays emitted from the Ge(,)Ge reaction were measured by using a -ray spectrometer (STELLA) which consists of eight clover-type Ge detectors and BGO Compton-suppressors. Many unknown -ray transitions, in addition to the known one, were seen in the energy spectrum. The new levels and the new transition -rays in Ge are reported.
Sugino, Kazuteru; Ishikawa, Makoto; Yokoyama, Kenji; Nagaya, Yasunobu; Chiba, Go; Hazama, Taira; Kugo, Teruhiko; Numata, Kazuyuki*; Iwai, Takehiko*; Jin, Tomoyuki*
Journal of the Korean Physical Society, 59(2), p.1357 - 1360, 2011/08
In order to improve the prediction accuracy of core performances in the fast reactor core design study, the unified cross-section set has been developed in Japan. The unified cross-section set, which combines a wide range of integral experimental information with differential nuclear data, is produced by using the cross-section adjustment technique based on the Bayesian parameter-estimation theory. A new set ADJ2010 is currently under development. The present paper describes the results of the cross-section adjustment for ADJ2010 which is based on the JENDL-4.0 data. The evaluation of the core design accuracy for a commercial power fast reactor core is also discussed. ADJ2010 will be released soon and will be expected to be utilized for core design of future fast reactors.
Journal of the Korean Physical Society, 59(2), p.1347 - 1352, 2011/08
The status of application study of nuclear data in JAEA is introduced in the following categories, theoretical and study and code development, experiment and extension of experimental database and application to reactor core analysis including the fuel cycle back-end field. Sensitivities of fission product concentrations of LWR burned fuel to nuclear data have been evaluated based on the depletion perturbation theory. Important nuclear data are specified for the accurate prediction of fission product concentrations. Extended bias factor methods are applied for the uncertainty evaluation of a fast breeder reactor core. From the application, the extended bias factor methods powerfully eliminate the uncertainty due to cross section errors by utilizing a number of integral data.
Kiyanagi, Yoshiaki*; Kino, Koichi*; Furusaka, Michihiro*; Hiraga, Fujio*; Kamiyama, Takashi*; Kato, Kiyoshi*; Igashira, Masayuki*; Katabuchi, Tatsuya*; Mizumoto, Motoharu*; Oshima, Masumi; et al.
Journal of the Korean Physical Society, 59(2), p.1781 - 1784, 2011/08
The project of the comprehensive nuclear data research for the development of the advanced reactor systems had been executed successfully by eight organizations from 2005 to 2009. In this project, we constructed the pulsed neutron beamline that was aimed to obtain neutron capture cross-sections of long-lived fission products and minor actinides accurately. The energy spectra, spatial distributions, and pulses of the beam were studied by measurements and simulation calculations, and they were found to be consistent with those of the beamline design. In this paper, we present the overview of the project and the properties of the neutron beam provided by this beam line.
Utsunomiya, Hiroaki*; Goriely, S.*; Akimune, Hidetoshi*; Harada, Hideo; Kitatani, Fumito; Goko, Shinji*; Toyokawa, Hiroyuki*; Yamada, Kawakatsu*; Lui, Y.-W.*
Journal of the Korean Physical Society, 59(2), p.1713 - 1716, 2011/08