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Nakayama, Shinsuke
Kaku Deta Nyusu (Internet), (133), p.88 - 99, 2022/10
The content of the paper that received the Paper Award of Atomic Energy Society of Japan in 2021 is outlined. Although the use of deuteron accelerator-based neutron sources has been proposed in various fields, deuteron nuclear database accurate enough to be applied to the design study of such neutron sources had not been developed. Under these situations, we had developed a deuteron nuclear database, JENDL/DEU-2020. It contains evaluated deuteron nuclear data for light nuclei (
Li, 
Be, 
C), which are candidates for deuteron beam irradiation targets of the neutron sources. Evaluation of JENDL/DEU-2020 was performed by using the code system DEURACS with further modifications. In order to validate the accuracy of the database, simulations using the particle transport code were performed under various conditions with different target nuclides and incident deuteron energies, and the results were compared with the available experimental data. As a result, it was found that JENDL/DEU-2020 significantly improves the prediction accuracy of experimental data under a wider range of conditions than other nuclear reaction databases or the nuclear reaction models implemented in transport calculation codes.
Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*; Ogata, Kazuyuki*
Few-Body Systems, 63(1), p.4_1 - 4_6, 2022/03
Times Cited Count：0 Percentile：0(Physics, Multidisciplinary)Intensive neutron sources using deuteron accelerators have been proposed for not only science and engineering fields but also medical applications. For the engineering design of such facilities, accurate and comprehensive nuclear data of deuteron-induced reactions are indispensable. However, it is difficult to meet the requirement by employing experimental data alone. Thus, theoretical model calculations play a key role in completing the necessary nuclear data by interpolation and extrapolation of experimental data. Under the above situations, we have been developing a code system dedicated for deuteron-induced reactions, called DEURACS. In the present work, calculations using DEURACS are compared with available experimental data and validation of the present modelling in DEURACS is discussed. Moreover, the importance of consideration of the breakup processes for accurate prediction of deuteron-induced reactions is also presented.
Nakayama, Shinsuke
JAEA-Conf 2021-001, p.65 - 70, 2022/03
Since deuteron is a weakly bound system consisting of a proton and a neutron, it easily breaks up and emits a neutron through interaction with a target nucleus. Utilizing this property, intensive neutron sources using deuteron accelerators have been proposed for not only science and engineering fields but also medical applications. For design studies of such facilities, accurate and comprehensive nuclear data of deuteron-induced reactions are indispensable. Toward evaluation of deuteron nuclear data, we have developed a code system dedicated for deuteron-induced reactions, called DEURACS. In DEURACS, breakup processes of incident deuteron are taken into account. DEURACS was so far successfully applied to analyses of production of nucleons, composite particles up to 
= 4, and residual nuclei. In this talk, we will present the results of these analyses and discuss how important it is to consider the breakup processes for accurate prediction of deuteron-induced reactions. Moreover, we have recently developed JENDL/DEU-2020, a deuteron nuclear database for Li, Be, and C up to 200 MeV. DEURACS was employed for evaluation of JENDL/DEU-2020. Validation of JENDL/DEU-2020 was carried out by the simulation with the Monte Carlo transport codes. These validation results will also be presented.
Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*; Ogata, Kazuyuki*
Journal of Nuclear Science and Technology, 58(7), p.805 - 821, 2021/07
Times Cited Count：20 Percentile：96.99(Nuclear Science & Technology)Intensive fast neutron sources using deuteron accelerators have been proposed for various applications. To contribute to the design study of such neutron sources, a deuteron nuclear data library for Li, Be, and C up to 200 MeV, JENDL/DEU-2020 is developed. The evaluation of JENDL/DEU-2020 are performed by employing the code system DEURACS with particular attention to neutron production data. Toward the evaluation of JENDL/DEU-2020, some modifications are made to DEURACS. The validation of the library is performed though simulation with the Monte Carlo transport calculation codes. From the simulation, it is shown that the calculation results based on JENDL/DEU-2020 reproduce the measured neutron production data well in the incident energies up to 200 MeV. The new library is expected to make a large contribution to diverse design studies of deuteron accelerator neutron sources.
ZnO using polyethylene by accelerator neutronsTsukada, Kazuaki; Nagai, Yasuki*; Hashimoto, Shintaro; Minato, Futoshi; Kawabata, Masako*; Hatsukawa, Yuichi*; Hashimoto, Kazuyuki*; Watanabe, Satoshi*; Saeki, Hideya*; Motoishi, Shoji*
Journal of the Physical Society of Japan, 89(3), p.034201_1 - 034201_7, 2020/03
Times Cited Count：2 Percentile：22.16(Physics, Multidisciplinary)We found anomalously large yields of 
Ga, 
Ga, 
Zn and 
Cu by neutron irradiation on a ZnO sample in a polyethylene shield. Neutron beams are generated from the Be(
) reaction for 50 MeV deuterons. The yields obtained were more than 20 times larger than those in the unshielded sample. On the other hand, the yields of Ga, Ga, Zn and Cu from a metallic Zn sample and the yields of Cu, 
Ni and Zn from the ZnO and Zn samples were almost insensitive to the shield conditions. This finding would provide us a unique capability of accelerator neutrons to simultaneously produce a large amount of several radioisotopes, including proton induced reaction products, by using a single sample. The experimental data were compared with the yields estimated by using the Particle and Heavy Ion Transport code System and the result was discussed.
Nakayama, Shinsuke
Kaku Deta Nyusu (Internet), (120), p.19 - 25, 2018/06
Toward development of accurate deuteron nuclear data, we have been developing a computational code dedicated for the deuteron-induced reaction, called DEURACS. The author presented the developmental status and the future outlook of DEURACS in the joint session of nuclear data subcommittee and sigma special advisory committee, and contributed the outline of the presentation to Nuclear Data News. From our preceding work, it has become possible to predict the 
reactions on light nuclei and the 
reactions. These reactions are important in relation to evaluation of neutron sources and tritium production, respectively. In the future, we plan to improve theoretical models implemented in DEURACS for accurate prediction of nuclide production cross-section on medium-heavy nuclei.
Watanabe, Yukinobu*; Kin, Tadahiro*; Araki, Shohei*; Nakayama, Shinsuke; Iwamoto, Osamu
EPJ Web of Conferences, 146, p.03006_1 - 03006_6, 2017/09
Times Cited Count：2 Percentile：78.04(Nuclear Science & Technology)The design of neutron sources requires comprehensive nuclear data of deuteron-induced reactions. Therefore, we have launched a research project on deuteron nuclear data, which is composed of measurements, theoretical model code development, cross section evaluation, and application to production of radioisotopes for medical use. Our goal is to develop a state-of-art deuteron nuclear data library up to 200 MeV necessary for the design of accelerator neutron sources with deuteron beam. The present status is reported in the presentation.
Saegusa, Jun; Yoshizawa, Michio; Tanimura, Yoshihiko; Yoshida, Makoto; Yamano, Toshiya*; Nakaoka, Hiroshi*
Nuclear Instruments and Methods in Physics Research A, 516(1), p.193 - 202, 2004/01
Times Cited Count：16 Percentile：70(Instruments & Instrumentation)Energy responses of three types of Japanese rem counters were evaluated by Monte Carlo simulations and measurements. The energy responses for thermal neutrons, monoenergetic neutrons with energies up to 15.2 MeV were evaluated as well as for neutrons from such radionuclide sources as 
Cf. The calculated results were corroborated with the measured ones. Angular dependence of the response and dose equivalent response was also evaluated. As a result, the reliable energy responses were obtained by careful simulations of the proportional counter, moderator and absorber of the rem counters. Furthermore, discussions were made about the relationship between pressure of counting gas and sensitivity of the rem counter. By using the obtained responses, relations of predicted readings of the rem counters and true dose equivalent were studied for various workplace spectra.
Nakayama, Shinsuke
no journal, ,
Since deuteron is a weakly bound nucleus consisting of a proton and a neutron, it easily break up and emit a neutron while interacting with other nuclei. By utilizing this property, highly efficient neutron sources using deuteron accelerators have been proposed. Accurate and comprehensive nuclear data of deuteron-induced reactions are indispensable for the engineering design of such facilities. However, TENDL, which is the only deuteron nuclear data file currently available is not necessarily enough for the requirement. Under the above situation, toward development of an accurate deuteron nuclear data file, we have been developing a code system dedicated for deuteron-induced reactions, called DEURACS. The present status and the future outlook of development of DEURACS will be presented.
Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*; Ogata, Kazuyuki*
no journal, ,
Intensive neutron sources using deuteron accelerators have been proposed for various applications such as irradiation testing of fusion reactor materials and production of medical radioisotopes. To contribute to the design study of such neutron sources, a deuteron reaction data file for light nuclei (Li-6,7, Be-9, C-12,13), JENDL/DEU-2020 was developed. In addition, the validation of it by the simulation with the codes such as PHITS was performed. As a result, the simulation based on JENDL/DEU-2020 reproduced the measured thick-target neutron yields better than those with the reaction models implemented in PHITS.
Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*; Ogata, Kazuyuki*
no journal, ,
Intensive neutron sources using deuteron accelerators have been proposed for various applications such as irradiation testing of fusion reactor materials and production of medical radioisotopes. To contribute to the design study of such neutron sources, a deuteron reaction data file for light nuclei (Li-6,7, Be-9, C-12,13), JENDL/DEU-2020 was developed. In addition, the validation of it was performed by the simulation with the Monte Carlo transport codes such as PHITS. As a result, the simulation using JENDL/DEU-2020 reproduced the measured thick-target neutron yields better than those using the deuteron sub-library of TENDL and the reaction models implemented in PHITS, respectively.
Hashimoto, Shintaro; Nagai, Yasuki*; Minato, Futoshi; Tsukada, Kazuaki
no journal, ,
Study for radioisotopes (RIs) production using accelerator neutron sources plays an important role in development of production method to supply stably RIs for medical use. We measured yields of not only 
Cu produced by neutrons but also 
Ga by protons in ZnO samples irradiated by neutrons from Be(d,n) reaction with 40-50 MeV deuterons, and developed a powerful method to estimate the yields using a general purpose Monte Carlo particle transport simulation mode PHITS with cross section data of the (d,n) reaction and JENDL-4.0/HE. We found a good agreement between new measured yields and estimated results within a factor of 3. Furthermore, we experimentally observed that yields of Ga are enhanced by covering the samples with polyethylene blocks. However, PHITS cannot reproduce the enhancement probably due to insufficient description of scattered neutrons form the blocks in the calculation.
Yamamoto, Kazuyoshi; Xu, P. G.; Iwamoto, Chihiro*; Takamura, Masato*; Otake, Yoshie*; Shobu, Takahisa
no journal, ,
no abstracts in English
