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Journal Articles

Study of the Li($$d,xn$$) reaction for the development of accelerator-based neutron sources

Watanabe, Yukinobu*; Sadamatsu, Hiroki*; Araki, Shohei*; Nakano, Keita*; Kawase, Shoichiro*; Kin, Tadahiro*; Iwamoto, Yosuke; Satoh, Daiki; Hagiwara, Masayuki*; Yashima, Hiroshi*; et al.

EPJ Web of Conferences, 239, p.20012_1 - 20012_4, 2020/09

Accelerator-based neutron sources induced by deuteron beams are attractive for study of nuclear transmutation of radioactive waste as well as radiation damage for fusion reactor materials. In the present work, we have carried out a Double Differential cross section (DDX) measurement for Li at 200 MeV in the Research Center for Nuclear Physics (RCNP), Osaka University. A deuteron beam accelerated to 200 MeV was transported to the neutron experimental hall and focused on a thin Li target. Emitted neutrons from the target were detected by two different-size EJ301 liquid organic scintillators located at two distances of 7 m and 20 m, respectively. The neutron DDXs were measured at six angles from 0$$^{circ}$$ to 25$$^{circ}$$). The neutron detection efficiencies of the detectors were calculated by SCINFUL-QMD code. We will present the results of the present DDX measurement and compare them with theoretical model calculations with DEURACS and PHITS.

Journal Articles

Recent progress of a code system DEURACS toward deuteron nuclear data evaluation

Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*

EPJ Web of Conferences, 239, p.03014_1 - 03014_4, 2020/09

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.

Journal Articles

Spallation and fragmentation cross sections for 168 MeV/nucleon $$^{136}$$Xe ions on proton, deuteron, and carbon targets

Sun, X. H.*; Wang, H.*; Otsu, Hideaki*; Sakurai, Hiroyoshi*; Ahn, D. S.*; Aikawa, Masayuki*; Fukuda, Naoki*; Isobe, Tadaaki*; Kawakami, Shunsuke*; Koyama, Shumpei*; et al.

Physical Review C, 101(6), p.064623_1 - 064623_12, 2020/06

 Times Cited Count:0 Percentile:100(Physics, Nuclear)

The spallation and fragmentation reactions of $$^{136}$$Xe induced by proton, deuteron and carbon at 168 MeV/nucleon were studied at RIKEN Radioactive Isotope Beam Factory via the inverse kinematics technique. The cross sections of the lighter products are larger in the carbon-induced reactions due to the higher total kinetic energy of carbon. The energy dependence was investigated by comparing the newly obtained data with previous results obtained at higher reaction energies. The experimental data were compared with the results of SPACS, EPAX, PHITS and DEURACS calculations. These data serve as benchmarks for the model calculations.

Journal Articles

JENDL/ImPACT-2018; A New nuclear data library for innovative studies on transmutation of long-lived fission products

Kunieda, Satoshi; Furutachi, Naoya; Minato, Futoshi; Iwamoto, Nobuyuki; Iwamoto, Osamu; Nakayama, Shinsuke; Ebata, Shuichiro*; Yoshida, Toru*; Nishihara, Kenji; Watanabe, Yukinobu*; et al.

Journal of Nuclear Science and Technology, 56(12), p.1073 - 1091, 2019/12

 Times Cited Count:1 Percentile:53.3(Nuclear Science & Technology)

A new nuclear data library, JENDL/ImPACT-2018, is developed for an innovative study on the transmutation of long-lived fission products. Nuclear reaction cross- sections are newly evaluated for incident neutrons and protons up to 200 MeV for 163 nuclides including long-lived nuclei such as $$^{79}$$Se, $$^{93}$$Zr, $$^{107}$$Pd and $$^{135}$$Cs. Our challenge is an evaluation of cross-sections for a number of unstable nuclei over a wide energy range where the experimental data are very scarce. We estimated cross- sections based on a nuclear model code CCONE that incorporates an advanced knowledge on the nuclear structure theory and a model-parameterization based on a new experimental cross-sections measured by the inverse kinematics. Through comparisons with available experimental data on the stable isotopes, it is found that the present data give predictions of cross-sections better than those in the existing libraries.

Journal Articles

Consistent description of light composite particle emission in deuteron-induced reactions

Nakayama, Shinsuke; Iwamoto, Osamu; Watanabe, Yukinobu*

Physical Review C, 100(4), p.044603_1 - 044603_8, 2019/10

 Times Cited Count:0 Percentile:100(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 $$(d,xt)$$, $$(d,xmathrm{^{3}He})$$, and $$(d,xalpha)$$ reactions in the target mass range $$27 leqslant A leqslant 90$$. 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.

Journal Articles

Enhancement of element production by incomplete fusion reaction with weakly bound deuteron

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:4 Percentile:28.2(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 $$^{107}$$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.

Journal Articles

International Conference on Nuclear Data for Science and Technology (ND2019), 3; Evaluation and theory

Nakayama, Shinsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Hashimoto, Shintaro

Kaku Deta Nyusu (Internet), (123), p.53 - 59, 2019/06

The 2019 International Conference on Nuclear Data for Science and Technology (ND2019) was held at the China National Convention Center on May 19-24, 2019. The series of the ND conferences are the largest conferences in nuclear data research field that are held every three years. In this paper, as a part of the conference reports of ND2019, the authors gave summaries of the presentations on nuclear data evaluation and theory conducted at the conference.

Journal Articles

Role of breakup processes in deuteron-induced spallation reactions at 100-200 MeV/nucleon

Nakayama, Shinsuke; Furutachi, Naoya; Iwamoto, Osamu; Watanabe, Yukinobu*

Physical Review C, 98(4), p.044606_1 - 044606_8, 2018/10

 Times Cited Count:6 Percentile:22.78(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 $$^{93}$$Zr and $$^{107}$$Pd at $$100-200$$ 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.

Journal Articles

Calculation of neutron cross-sections on copper-63 and -65

Nakayama, Shinsuke

Journal of Nuclear Science and Technology, 55(6), p.614 - 622, 2018/06

 Times Cited Count:0 Percentile:100(Nuclear Science & Technology)

Toward the development of the next version of Japanese Evaluated Nuclear Data Library (JENDL) general-purpose file, we calculate neutron cross-sections on $$^{63,65}$$Cu from 50 keV to 20MeV, which is the incident energy range above the resolved resonance region in JENDL-4.0. A dispersive optical model potential is adopted with a coupled-channel method for interaction between neutron and $$^{63, 65}$$Cu. Direct, pre-equilibrium, and compound processes are taken into account in the calculation. All cross-sections, differential and double-differential cross-sections are consistently calculated with a single set of model parameters. The calculation results reproduce the measured data very well. In addition, disagreement between the calculated and experimental values seen in an integral test for the $$^{63}$$Cu$$(n,alpha)^{60}$$ reaction is improved by using the cross-section data obtained from the present work.

Journal Articles

Joint Session of Nuclear Data Subcommittee and Sigma Special Advisory Committee; Present status and future of nuclear data evaluation code in Japan, 3; Development of DEURACS for prediction of deuteron-induced reaction cross section

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 $$(d,xn)$$ reactions on light nuclei and the $$(d,xt)$$ 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.

Journal Articles

Theoretical model analysis of $$(d,xn)$$ reactions on $$^7$$Li at 25, 40, and 102 MeV

Sadamatsu, 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 $$^7$$Li target. The calculated double differential cross sections for $$(d,xn)$$ reactions at incident energies of 25, 40, and 102 MeV are compared with the measured ones, and the applicability of DEURACS is discussed.

Journal Articles

Theoretical model analysis of composite-particle emission from deuteron-induced reactions

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 $$(d,xd)$$, $$(d,xt)$$, $$(d,x^3 {rm He})$$, and $$(d,xalpha)$$ reactions on $$^{27}$$Al and $$^{58}$$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.

Journal Articles

Deuteron nuclear data for the design of accelerator-based neutron sources; Measurement, model analysis, evaluation, and application

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:0 Percentile:100

The design of $$(d,xn)$$ 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.

Journal Articles

Development of a code system DEURACS for theoretical analysis and prediction of deuteron-induced reactions

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:1 Percentile:24.33

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 $$(d,xn)$$ reactions is extended to higher incident energy up to nearly 100 MeV and also DEURACS is applied to $$(d,xd)$$ reactions at 80 and 100 MeV. The DEURACS calculations reproduce the experimental double-differential cross sections for the $$(d,xn)$$ and $$(d,xd)$$ reactions well.

Journal Articles

Status of the JENDL project

Iwamoto, Osamu; Shibata, Keiichi; Iwamoto, Nobuyuki; Kunieda, Satoshi; Minato, Futoshi; Ichihara, Akira; Nakayama, Shinsuke

EPJ Web of Conferences, 146, p.02005_1 - 02005_6, 2017/09

 Times Cited Count:0 Percentile:100

Journal Articles

Analysis of $$(d,xn)$$ reactions on $$^{9}$$Be and $$^{12}$$C

Nakayama, Shinsuke; Kono, Hiroshi*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ogata, Kazuyuki*

RCNP Annual Report 2016 (Internet), 2 Pages, 2017/05

We are conducting a theoretical research on deuteron-induced reaction together with Kyushu University and Research Center for Nuclear Physics (RCNP) of Osaka University. The research outcomes achieved in fiscal year 2016 are summarized as a part of the annual report of RCNP. In recent years, accelerator neutron sources using $$(d,xn)$$ reactions on light nuclei (Li, Be, C, etc.) are proposed for applications in various fields. Engineering design of such facilities requires accurate prediction of $$(d,xn)$$ reactions on light nuclei in a wide incident energy range. Therefore, we have developed a physics-based computational code system dedicated for deuteron-induced reactions, called DEURACS. In fiscal year 2016, we calculated double-differential neutron yields from deuteron bombardment on thick $$^{9}$$Be and $$^{12}$$C targets, and the calculation reproduced the experimental data quantitatively well in the incident energy range up to 50 MeV. From the results, it has been found that DEURACS can accurately predict $$(d,xn)$$ reactions on light nuclei in a wide incident energy range. In addition, component-by-component analysis has revealed that the nonelastic breakup reactions make the most dominant contribution to neutron production.

Journal Articles

Evaluation of neutron nuclear data on copper isotopes by a consistent method

Nakayama, Shinsuke

JAEA-Conf 2016-004, p.147 - 152, 2016/09

Copper is an important element relevant to heat sink material for fusion reactors, structural material for accelerator-driven systems, and so on. Therefore, more precise neutron nuclear data on copper isotopes are currently required. In addition, covariance data are also required to estimate uncertainties of various integral quantities obtained from calculation using the nuclear data. Covariance includes correlated uncertainties between different nuclear data, e.g. cross sections of different reactions. In evaluation on $$^{63,65}$$Cu of JENDL-4.0, the cross sections and angular distributions for several reactions were calculated by various computational codes. Towards preparation of covariance data, we evaluated neutron nuclear data on $$^{63,65}$$Cu by a consistent method using the CCONE code.

Journal Articles

Theoretical model analysis of $$(d,xn)$$ reactions on beryllium

Kono, Hiroshi*; Watanabe, Yukinobu*; Nakayama, Shinsuke; Iwamoto, Osamu; Ye, T.*; Ogata, Kazuyuki*

JAEA-Conf 2016-004, p.165 - 170, 2016/09

For engineering design of deuteron accelerator neutron sources, accurate nuclear data of deuteron-induced reactions on neutron converter (Li, Be, C, etc.) and accelerator structure material (Fe, Cr, Ni, etc.) are indispensable. Therefore we have developed a computational code system based on physics models dedicated for deuteron nuclear data evaluation. In the present study, we have analyzed the $$(d,xn)$$ reactions on beryllium at incident deuteron energies up to 65 MeV. Since there is a lot of experimental Thick Target Neutron Yields (TTNYs), double-differential $$(d,xn)$$ cross sections are calculated by the code system and then are converted to TTNYs. It is found that the calculated TTNYs reproduce the experimental ones fairly well except in the low neutron energy region.

Journal Articles

Theoretical model analysis of $$(d,xn)$$ reactions on $$^9$$Be and $$^{12}$$C at incident energies up to 50 MeV

Nakayama, Shinsuke; Kono, Hiroshi*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ogata, Kazuyuki*

Physical Review C, 94(1), p.014618_1 - 014618_9, 2016/07

 Times Cited Count:13 Percentile:18.26(Physics, Nuclear)

Double-differential thick target neutron yields (TTNYs) from deuteron bombardment on thick Be and C targets are analyzed using the DEURACS (DEUteron-induced Reaction Analysis Code System). The calculated TTNYs reproduced the experimental ones quantitatively well in the incident energy range up to 50 MeV. In addition, it was found that the proton stripping reaction makes the most dominant contribution to neutron production. From the analysis, we conclude that the DEURACS is applicable to $$(d,xn)$$ reactions and modeling of the stripping reaction is essential to predict neutron production yields accurately.

Journal Articles

Modelling and analysis of nucleon emission from deuteron-induced reactions at incident energies up to 100 MeV

Nakayama, Shinsuke; Kono, Hiroshi*; Watanabe, Yukinobu*; Iwamoto, Osamu; Ye, T.*; Ogata, Kazuyuki*

EPJ Web of Conferences, 122, p.04004_1 - 04004_9, 2016/06

 Times Cited Count:4 Percentile:8.54

In recent years, accelerator neutron sources using deuteron-induced reactions on $$^7$$Li, $$^9$$Be, $$^{12}$$C, etc., are proposed for applications in various fields. Engineering design of such facilities requires deuteron nuclear data in a broad incident energy range. We have developed a computational code system dedicated for deuteron nuclear data evaluation in combination with some theoretical models. The code system has been applied to analyses of double-differential $$(d,xp)$$ cross sections for $$^{12}$$C, $$^{27}$$Al, and $$^{58}$$Ni at incident energies up to 100 MeV. On the other hand, there is few experimental double-differential $$(d,xn)$$ cross sections. Therefore, double-differential thick target neutron yields for light nuclei such as $$^9$$Be and $$^{12}$$C are calculated and compared with experimental data. The presentation will show the validation result of the present modelling for nucleon emissions from deuteron-induced reactions through comparison with available experimental data.

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