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and 
reactions and its implications for a phenomenological reaction modelNakada, Hibiki*; Nakayama, Shinsuke; Yoshida, Kazuki; Watanabe, Yukinobu*; Ogata, Kazuyuki*
Physical Review C, 110(1), p.014616_1 - 014616_8, 2024/07
Times Cited Count：0 Percentile：0.00(Physics, Nuclear)Previous studies have revealed the importance of introducing surface correction into a phenomenological model for inclusive 
and reactions, and these findings have contributed significantly to the improvement of nuclear data evaluation. However, the necessity for the surface correction in an inclusive reaction has hardly been investigated. The energy spectra and their radial distributions for the and reactions are calculated by the one-step semiclassical distorted wave model. The radial distribution of the energy spectra for the reaction is shifted toward the outer region of the nucleus compared to the reaction. Based on this finding, we consider a larger surface correction into a phenomenological model for the reaction than that for the reaction, and calculated values reproduce the experimental spectra well. The peripherality of the reaction is more prominent than that of the reaction. The stronger surface correction thus should be introduced for the reaction than for the reaction.
Nakayama, Shinsuke
Journal of Nuclear Science and Technology, 60(12), p.1447 - 1453, 2023/12
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)The d+Be neutron source is a candidate for transportable neutron source for on-site nondestructive inspection of infrastructure facilities such as bridges, tunnels and so on. The applicability of the d+Be neutron source to a transportable fast neutron source is explored by Monte Carlo particle transport simulations with PHITS and JENDL-5. The simulation results show that by increasing the shielding thickness by about 1.5 times, it is possible to realize the d+Be neutron source with the comparable performance to another candidate, the 2.5-MeV p+Li neutron source, at lower beam energy.
Zr + d reaction cross sections measured at 28 MeV/nucleonChillery, T.*; Hwang, J.*; Dozono, Masanori*; Imai, Nobuaki*; Michimasa, Shinichiro*; Sumikama, Toshiyuki*; Chiga, Nobuyuki*; Ota, Shinsuke*; Nakayama, Shinsuke; 49 of others*
Progress of Theoretical and Experimental Physics (Internet), 2023(12), p.121D01_1 - 121D01_11, 2023/12
Times Cited Count：4 Percentile：59.55(Physics, Multidisciplinary)The deuteron is a loosely bound system which can easily break up into its constituent proton and neutron whilst in the presence of Coulomb and nuclear fields. Previous experimental studies have shown that this breakup process has a significant impact on residual nucleus production from deuteron bombardment in the high energy range of 50 - 210 MeV/nucleon. However, there remains a lack of cross-section data at energies below 50 MeV/nucleon. The current study determined Zr + d reaction cross sections under inverse kinematics at approximately 28 MeV/nucleon using the BigRIPS separator, OEDO beamline, and SHARAQ spectrometer. Cross sections from this research were compared with previous measurements and theoretical calculations. The experimental results show a large enhancement of the production cross sections of residual nuclei, especially those produced from a small number of particle emissions, compared to the proton-induced reaction data at similar bombarding energy. The DEURACS calculation, which quantitatively takes deuteron-breakup effects into account, reproduces the data well. As a long-lived fission product, Zr remains a challenge for nuclear waste disposal and treatment. This study's low-energy data may assist future consideration of nuclear-waste treatment facilities, where Zr + d may feasibly transmute the waste into short-lived/stable nuclei.
Liu, H.*; Nakayama, Shinsuke; Lei, J.*; Ren, Z.*
Physical Review C, 108(1), p.014617_1 - 014617_8, 2023/07
In this paper, we study deuteron-induced inclusive breakup reaction and explore the 
and 
reactions for light and medium mass nuclei. Using the models of Ichimura, Austern, and Vincent and Glauber, we scrutinize the double differential cross-section of nonelastic breakup and compare the results for various reaction systems. Our findings indicate that the Glauber model, combined with a quantum 
-matrix, produces remarkable results in the deuteron-induced inclusive breakup reaction. While both models are proficient in predicting the outcomes of light and medium mass nuclei, the reaction showcases higher consistency than the reaction. Nevertheless, there are still significant discrepancies between experimental and theoretical cross-sections that require further investigation and analysis. This study opens up a new realm of possibilities for future research in the field.
Nakayama, Shinsuke; Iwamoto, Osamu; Sublet, J.-Ch.*
EPJ Web of Conferences, 284, p.14011_1 - 14011_4, 2023/05
JENDL-5, the latest version of the Japanese evaluated nuclear data library, includes several sub-libraries to contribute to various applications. In this paper, we outline the evaluation and validation of the deuteron reaction sub-library developed mainly for the design of accelerator-based neutron sources and the alpha-particle reaction sub-library developed mainly for use in the back-end field. As for the deuteron sub-library, the data for 
Li, 
Be, and 
C from JENDL/DEU-2020 were partially modified and adopted. The data up to 200 MeV for 
Al, 
Cu, and Nb, which are important as accelerator structural materials, were newly evaluated based on the calculations with the DEURACS code. As for the alpha-particle sub-library, the data up to 15 MeV for 18 light nuclides from Li to Si isotopes were evaluated based on the calculations with the CCONE code, and then only the neutron production cross sections were replaced with the data of JENDL/AN-2005. Validation on neutron yield by Monte Carlo transport simulations was performed for both sub-libraries. As a result, it was confirmed that the simulations based on the sub-libraries showed good agreement with experimental data.
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; Furutachi, Naoya; Iwamoto, Osamu; Watanabe, Yukinobu*
NEA/NSC/R(2020)4 (Internet), p.345 - 349, 2022/10
Long-lived fission products (LLFPs) generated in nuclear reactors are strongly desired to be converted to stable or short-lived nuclides. Recently, it has been considered to transmute LLFPs by spallation reactions with high energy particles, and some experimental studies revealed that spallation reaction cross-sections induced by deuteron are larger than proton-induced ones. These results suggest the possibility that nuclear transmutation of LLFPs using deuteron beams is more efficient than one using proton beams. On the other hand, we have been developing a code system dedicated for deuteron-induced reactions, called DEURACS. DEURACS has been originally developed to contribute to the design of deuteron accelerator neutron sources. In the present study, we apply DEURACS to calculation of deuteron-induced spallation reactions on LLFPs. Through comparison with measured data, the applicability of DEURACS will be discussed.
Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*; Ogata, Kazuyuki*
Few-Body Systems, 63(1), p.4_1 - 4_6, 2022/03
Times Cited Count：1 Percentile：15.48(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：28 Percentile：95.85(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.
) reaction at 12, 20, and 30 MeVPatwary, M. K. A*; Kin, Tadahiro*; Aoki, Katsumi*; Yoshinami, Kosuke*; Yamaguchi, Masaya*; Watanabe, Yukinobu*; Tsukada, Kazuaki; Sato, Nozomi*; Asai, Masato; Sato, Tetsuya; et al.
Journal of Nuclear Science and Technology, 58(2), p.252 - 258, 2021/02
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)While designing deuteron accelerator neutron sources for radioisotopes production, nuclear data for light elements such as Li, Be, and C have been systematically measured in the deuteron energy range from a few MeV to around 50 MeV. Currently, the experimental data available on double-differential thick-target neutron yields (DDTTNYs) is insufficient, especially for deuteron energies between 18 and 33 MeV. In this study, we measured the DDTTNYs of () reactions on 
C target for incident deuteron energies of 12, 20, and 30 MeV using the multiple-foils activation method to improve nuclear data insufficiency. We applied the GRAVEL code for the unfolding process to derive the DDTTNYs. The results were compared with the calculation by DEURACS. The present data were also used to confirm the systematics of the differential neutron yields at 0
and total neutron yield per incident deuteron in the wide range of deuteron energy.
Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*
EPJ Web of Conferences, 239, p.03014_1 - 03014_4, 2020/09
Times Cited Count：2 Percentile：80.29(Nuclear Science & Technology)Intensive neutron sources using deuteron accelerators have been proposed for various applications such as irradiation test for fusion reactor materials and production of radioisotopes for medical use. In addition, transmutation system using deuteron-induced spallation reactions has been recently proposed for LLFPs. Accurate and comprehensive deuteron nuclear data are indispensable in the design study of such facilities. Under the above situations, we have been developing a code system dedicated for deuteron-induced reactions, which is called DEURACS. In the present work, calculations using DEURACS are compared with available experimental data up to 200 MeV such as DDXs for emission of neutron or light charged particles. We also analyze isotopic production cross sections of residual nuclei. Validation of the present modelling in DEURACS is discussed through comparison with the experimental data.
Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*
Physical Review C, 100(4), p.044603_1 - 044603_8, 2019/10
Times Cited Count：7 Percentile：52.35(Physics, Nuclear)The weakly-bound nature of the deuteron brings the complexity of deuteron-induced reactions compared to nucleon-induced ones, and is expected to affect various physical quantities observed in deuteron-induced reactions. Aiming to deep understanding and accurate prediction for the emission of light composite particle (LCP) in deuteron-induced reactions, we revise the computational system dedicated to deuteron-induced reactions, called DEURACS. The model by Iwamoto and Harada describing pre-equilibrium cluster emission which was successfully applied to LCP emission innucleon-induced reactions is integrated into the framework of DEURACS, in which the breakup processes of incident deuteron are explicitly taken into account. The phenomenological model by Kalbach is also adopted to estimate the contribution from the direct pickup process. Using the revised DEURACS, we analyze the 
, 
, and 
reactions in the target mass range 
. Regardless of the targets, the calculation results successfully reproduced the experimental data for each reaction, simultaneously. These results demonstrates that the LCP emission from the pre-equilibrium and compound nucleus processes in deuteron-induced reactions,which occupies a large part of the total LCP emission,can be described by the same theoretical models as used in nucleon-induced reactions when the breakup processes of incident deuteron are properly considered.
Wang, H.*; Otsu, Hideaki*; Chiga, Nobuyuki*; Kawase, Shoichiro*; Takeuchi, Satoshi*; Sumikama, Toshiyuki*; Koyama, Shumpei*; Sakurai, Hiroyoshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; et al.
Communications Physics (Internet), 2(1), p.78_1 - 78_6, 2019/07
Times Cited Count：10 Percentile：56.67(Physics, Multidisciplinary)Searching for effective pathways for the production of proton- and neutron-rich isotopes through an optimal combination of reaction mechanism and energy is one of the main driving forces behind experimental and theoretical nuclear reaction studies as well as for practical applications in nuclear transmutation of radioactive waste. We report on a study on incomplete fusion induced by deuteron, which contains one proton and one neutron with a weak binding energy and is easily broken up. This reaction study was achieved by measuring directly the cross sections for both proton and deuteron for 
Pd at 50 MeV/u via inverse kinematics technique. The results provide direct experimental evidence for the onset of a cross-section enhancement at high energy, indicating the potential of incomplete fusion induced by loosely-bound nuclei for creating proton-rich isotopes and nuclear transmutation of radioactive waste.
Nakayama, Shinsuke; Furutachi, Naoya; Iwamoto, Osamu; Watanabe, Yukinobu*
Physical Review C, 98(4), p.044606_1 - 044606_8, 2018/10
Times Cited Count：15 Percentile：72.92(Physics, Nuclear)Use of deuteron-induced spallation reactions at intermediate energies has recently been proposed for transmutation of several long-lived fission products (LLFPs). In the design study of a transmutation system using a deuteron primary beam, accurate cross section data of deuteron-induced reactions on the LLFPs are indispensable. In the present study, production cross sections of residual nuclei in the deuteron-induced reactions on Zr and Pd at 
MeV/nucleon are analyzed using DEURACS, in which the breakup processes are explicitly taken into account. The calculated values reproduced the experimental data quantitatively well. From a component-by-component analysis, it was found that the components of nucleon absorption make the significant contributions to residual nuclei production. This result strongly indicates that consideration of the breakup processes is essentially important to predict production of residual nuclei in deuteron-induced reactions.
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.
Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*
JAEA-Conf 2017-001, p.91 - 96, 2018/01
Toward evaluation of deuteron nuclear data, we have been developing a code system dedicated for the deuteron-induced reactions, called DEURACS. In the present work, we make an improvement in DEURACS and apply it to composite-particle emission from deuteron-induced reactions. The calculation using DEURACS reproduces the experimental double-differential cross sections of 
, , 
, and reactions on Al and 
Ni at incident energy of 80 MeV quantitatively well. From the results of the analyses, it is shown that the treatment of inelastic scattering and pick-up reaction processes is important in the calculation of deuteron-induced composite-particle emission.
reactions on 
Li at 25, 40, and 102 MeVSadamatsu, Hiroki*; Nakayama, Shinsuke; Watanabe, Yukinobu*; Iwamoto, Osamu; Ogata, Kazuyuki*
JAEA-Conf 2017-001, p.135 - 140, 2018/01
In recent years, the demand for intense neutron sources has been increasing in various applications such as nuclear transmutation of high-level radioactive waste and medical radioisotopes production. Deuteron accelerator-based neutron sources are promised as one of the candidates. Therefore, we have developed a code system dedicated for the deuteron-induced reactions, called DEURACS. In the present work, we focus on deuteron-induced neutron production from Li target. The calculated double differential cross sections for reactions at incident energies of 25, 40, and 102 MeV are compared with the measured ones, and the applicability of DEURACS is discussed.
Nakayama, Shinsuke; Kono, Hiroshi*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ye, T.*; Ogata, Kazuyuki*
EPJ Web of Conferences, 146, p.12025_1 - 12025_4, 2017/09
Times Cited Count：5 Percentile：91.33(Nuclear Science & Technology)Recently, intensive neutron sources using deuteron accelerator have been proposed for various applications. Accurate and comprehensive deuteron nuclear data library over wide ranges of target mass number and incident energy are indispensable for the design of deuteron accelerator neutron sources. Thus, we have developed an integrated code system dedicated for analysis and prediction of deuteron-induced reactions, which is called DEUteron-induced Reaction Analysis Code System (DEURACS). In the present work, the analysis of reactions is extended to higher incident energy up to nearly 100 MeV and also DEURACS is applied to reactions at 80 and 100 MeV. The DEURACS calculations reproduce the experimental double-differential cross sections for the and reactions well.
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：3 Percentile：83.31(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.
