Neutron energy spectra at 180 from 140 MeV proton incident reactions

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

https://doi.org/10.3938/jkps.59.1753

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.

Shielding experiments by the JASMIN collaboration at Fermilab, 2; Radioactivity measurement induced by secondary particles from the anti-proton production target

Yashima, Hiroshi*; Matsuda, Norihiro; Kasugai, Yoshimi; Nakashima, Hiroshi; Sakamoto, Yukio; Matsumura, Hiroshi*; Iwase, Hiroshi*; Kinoshita, Norikazu*; Boehnlein, D.*; Lautenschlager, G.*; et al.

Journal of the Korean Physical Society, 59(2), p.2051 - 2054, 2011/08

https://doi.org/10.3938/jkps.59.2051

The experiment was performed at the anti-proton (pbar) production target station in Fermi National Accelerator Laboratory. At the pbar target station, an anti-proton production target, consisted of Inconel and copper disks, were irradiated by 120 GeV proton beam. The beam intensity was 2.0 10 proton per second. Al, Nb, Cu, Au samples were set around the target to investigate the spatial and energy distribution of secondary particles emitted from the target. After irradiation, induced activities of samples were measured by using HPGe detector. The reaction rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. The reaction rates of these nuclides increase for samples placed on forward angle position. The angle dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results compared with the calculation. The calculated results generally agree with the experimental results within a factor of 3.

JENDL-4.0 integral testing for fission systems

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

https://doi.org/10.3938/jkps.59.1135

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.

Covariance evaluation for actinide nuclear data in JENDL-4

Iwamoto, Osamu; Nakagawa, Tsuneo; Chiba, Satoshi; Otsuka, Naohiko*

Journal of the Korean Physical Society, 59(2), p.1224 - 1229, 2011/08

https://doi.org/10.3938/jkps.59.1224

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.

Measurement of (,) cross sections of Se isotopes using laser-Compton scattering -rays

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

https://doi.org/10.3938/jkps.59.1836

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.

Measurements of neutron-capture cross sections of Cm and Cm at J-PARC/MLF/ANNRI

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

https://doi.org/10.3938/jkps.59.1828

Neutron-production double-differential cross sections from heavy-ion interactions

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

https://doi.org/10.3938/jkps.59.1741

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.

Applicability of pre-equilibrium coalescence model to evaluation of alpha-particle production cross sections

Kunieda, Satoshi; Fukahori, Tokio; Hirayama, Shusuke*; Watanabe, Yukinobu*

Journal of the Korean Physical Society, 59(2), p.911 - 914, 2011/08

https://doi.org/10.3938/jkps.59.911

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.

Implementation of a collimated DT neutron beam at the 1st target room of JAEA/FNS for new integral benchmark experiments

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

https://doi.org/10.3938/jkps.59.1949

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.

Prompt rays emitted from the neutron capture reaction of Ge

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

https://doi.org/10.3938/jkps.59.1832

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.