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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

Evaluation of gamma-ray strength function based on measured gamma-ray pulse-height spectra in time-of-flight neutron capture experiments

Iwamoto, Nobuyuki; Nakamura, Shoji; Kimura, Atsushi; Katabuchi, Tatsuya*; Rovira, G.*; Hara, Kaoru*; Iwamoto, Osamu

EPJ Web of Conferences, 239, p.17016_1 - 17016_4, 2020/09

Journal Articles

Calculation of athermal recombination corrected dpa cross sections for proton, deuteron and heavy-ion irradiations using the PHITS code

Iwamoto, Yosuke; Meigo, Shinichiro

EPJ Web of Conferences, 239, p.20011_1 - 20011_4, 2020/09

PHITS including the NRT model can calculate displacement cross sections of materials for various particle irradiations in wide energy range. Recently, Nordlund et al. provided the athermal recombination corrected (arc) displacement per atom (dpa) function providing more physically realistic descriptions of primary defect creation in materials. Therefore, the arc-dpa will be used for efficient predictions of the usable lifetime of materials in various accelerator facilities. In this work, the arc-dpa function related with the defect production efficiency was implemented in the radiation damage model in PHITS. As a result, for the displacement cross sections of Cu and W under proton irradiations with energies above 100 MeV, the arc-dpa cross sections are smaller than the NRT-dpa cross sections by a factor of about 3. In this presentation, we will present the arc-dpa cross sections for proton, deuteron and heavy-ion irradiations in the energy region between 100 MeV/u and 3 GeV/u.

Journal Articles

Utilizing nuclear data in delayed gamma-ray spectroscopy inverse Monte Carlo analysis

Rodriguez, D.; Abbas, K.*; Crochemore, J.-M.*; Koizumi, Mitsuo; Nonneman, S.*; Pedersen, B.*; Rossi, F.; Seya, Michio*; Takahashi, Toon

EPJ Web of Conferences, 239, p.17005_1 - 17005_5, 2020/09

Journal Articles

A Comprehensive study of spallation models for proton-induced spallation product yields utilized in transport calculation

Iwamoto, Hiroki; Meigo, Shinichiro; Matsuda, Hiroki

EPJ Web of Conferences, 239, p.06001_1 - 06001_6, 2020/09

no abstracts in English

Journal Articles

Measurement of nuclide production cross section for lead and bismuth with proton in energy range from 0.4 GeV to 3.0 GeV

Matsuda, Hiroki; Meigo, Shinichiro; Iwamoto, Hiroki; Maekawa, Fujio

EPJ Web of Conferences, 239, p.06004_1 - 06004_4, 2020/09

For the Accelerator-Driven nuclear transmutation System (ADS), nuclide production yield estimation in the lead-bismuth target is important to manage the target. However, experimental data of nuclide production yield by spallation and high-energy fission reactions are scarce. In order to obtain the experimental data, we experimented in J-PARC using $$^{mathrm{nat}}$$Pb and $$^{mathrm{209}}$$Bi samples. The samples were irradiated with protons at various kinematic energy points between 0.4 and 3.0 GeV. After the irradiation, the nuclide production cross section over $$^{mathrm{7}}$$Be to $$^{mathrm{183}}$$Re was obtained by spectroscopic measurement of decay gamma-rays from the samples with HPGe detectors. The present experimental results were compared with the evaluated data (JENDL-HE/2007) and the calculation with the PHITS code and the INCL++ code. The present experiment data showed consistency with other experimental data with better accuracy than other ones. In reactions to produce light nuclides, JENDL and calculation with the PHITS and INCL++ for $$^{mathrm{7}}$$Be production agreed with the data.$$^{mathrm{22}}$$Na production, however, underestimated about 1/10 times. For middle to heavy nuclide productions cases, both calculations agreed with the experiment by a factor of two. JENDL showed lower energy having a maximum value of excitation function maximal value than the experimental data.

Journal Articles

Measurement of displacement cross section of structural materials utilized in the proton accelerator facilities with the kinematic energy above 400 MeV

Meigo, Shinichiro; Matsuda, Hiroki; Iwamoto, Yosuke; Yoshida, Makoto*; Hasegawa, Shoichi; Maekawa, Fujio; Iwamoto, Hiroki; Nakamoto, Tatsushi*; Ishida, Taku*; Makimura, Shunsuke*

EPJ Web of Conferences, 239, p.06006_1 - 06006_4, 2020/09

R&D of the beam window is crucial in the ADS, which serves as a partition between the accelerator and the target region. Although the displacement per atom (DPA) is used to evaluate the damage on the window, experimental data on the displacement cross section is scarce in the energy region above 20 MeV. We started to measure the displacement cross section for the protons in the energy region between 0.4 to 3 GeV. The displacement cross section can be derived by resistivity change divided by the proton flux and the resistivity change per Frankel pair on cryo-cooled sample to maintain damage. Experiments were conducted at the 3 GeV proton synchrotron at the J-PARC Center, and copper was used as samples. As a result of comparison between the present experiment and the calculation of the NRT model, which is widely used for calculation of the displacement cross section, it was found that the calculation of the NRT model overestimated the experiment by about 3 times.

Journal Articles

Progress status in fabrication of HBC stripper foil for 3-GeV RCS at J-PARC in Tokai site

Yoshimoto, Masahiro; Yamazaki, Yoshio; Nakanoya, Takamitsu; Saha, P. K.; Kinsho, Michikazu

EPJ Web of Conferences, 229, p.01001_1 - 01001_7, 2020/02

In the 3-GeV Rapid Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), we adopted thick Hybrid type Boron-doped Carbon (HBC) stripper foil for the multi-turn H$$^{-}$$ charge-exchange injection. The HBC stripper foil developed at KEK has been successfully demonstrated to improve the foil lifetime significantly. Early manufacturing process of the stripper foil in the J-PARC had been carried out in following two steps: foil fabrication in KEK Tsukuba-site and foil preparation in JAEA Tokai-site. However, to proceed with the foil manufacturing in a same place efficiently, the carbon discharge arc-evaporation system for HBC stripper foil was removed from the Tsukuba-site and relocated in the Tokai-site. After reassembling of the carbon discharge arc-evaporation system, performance evaluation tests of new HBC foil which are produced at the JAEA Tokai site (J-HBC) are implemented at the TIARA facility of QST-Takasaki. As results of argon beam irradiation for lifetime evaluation, components analysis with RBS method, and impurity evaluation with micro-PIXE method, we can verify that the J-HBC foil performs pretty much equally to the original HBC foil. After the irradiation test by using 400MeV H$$^{-}$$ beam in the J-PARC RCS, user operation by using the J-HBC foil was successfully demonstrated for 10 days.

Journal Articles

Measurement of the angular distribution of $$gamma$$-rays after neutron capture by $$^{139}$$La for a T-violation search

Okudaira, Takuya; Shimizu, Hirohiko*; Kitaguchi, Masaaki*; Hirota, Katsuya*; Haddock, C. C.*; Ito, Ikuya*; Yamamoto, Tomoki*; Endo, Shunsuke*; Ishizaki, Kohei*; Sato, Takumi*; et al.

EPJ Web of Conferences, 219, p.09001_1 - 09001_6, 2019/12

Parity violating effects enhanced by up to 10$$^6$$ times have been observed in several neutron induced compound nuclei. There is a theoretical prediction that time reversal (T) violating effects can also be enhanced in these nuclei implying that T-violation can be searched for by making very sensitive measurements. However, the enhancement factor has not yet been measured in all nuclei. The angular distribution of the (n,$$gamma$$) reaction was measured with $$^{139}$$La by using a germanium detector assembly at J-PARC, and the enhancement factor was obtained. From the result, the measurement time to achieve the most sensitive T-violation search was estimated as 1.4 days, and a 40% polarized $$^{139}$$La target and a 70% polarized $$^3$$He spin filter whose thickness is 70 atm$$cdot$$cm are needed. Therefore high quality $$^3$$He spin filter is developed in JAEA. The measurement result of the (n,$$gamma$$) reaction at J-PARC and the development status of the $$^3$$He spin filter will be presented.

Journal Articles

Recent results from the LHCf and RHICf experiments

Ito, Yoshitaka*; Tanida, Kiyoshi; 30 of others*

EPJ Web of Conferences, 208, p.05004_1 - 05004_8, 2019/05

 Times Cited Count:0

Journal Articles

Transverse single spin asymmetry for very forward $$pi^0$$ production in polarized proton-proton collisions at $$sqrt s$$ = 510 GeV

Kim, M. H.*; Tanida, Kiyoshi; 20 of others*

EPJ Web of Conferences, 208, p.05007_1 - 05007_4, 2019/05

 Times Cited Count:0

Journal Articles

Evaluation of neutron capture cross section on $$^{205}$$Pb with photonuclear data

Iwamoto, Nobuyuki; Shizuma, Toshiyuki*

EPJ Web of Conferences, 178, p.06004_1 - 06004_3, 2018/05

 Times Cited Count:0 Percentile:100

Journal Articles

Developing reliable reaction gamma-ray data

Dimitriou, P.*; Belgya, T.*; Cho, Y.-S.*; Filipescu, D.*; Firestone, R.*; Goriely, S.*; Iwamoto, Nobuyuki; Kawano, Toshihiko*; Kopecky, J.*; Krticka, M.*; et al.

EPJ Web of Conferences, 178, p.06005_1 - 06005_3, 2018/05

 Times Cited Count:2 Percentile:7.79

no abstracts in English

Journal Articles

Heavy ion acceleration at J-PARC

Sato, Susumu; J-PARC Heavy Ion Collaboration*

EPJ Web of Conferences, 171, p.21002_1 - 21002_4, 2018/02

 Times Cited Count:0 Percentile:100

J-PARC is an accelerator, which provides a high-intensity proton beam. Recently as a very attractive project, the acceleration of heavy ions produced by supplementary ion sources, called J-PARC-HI, is seriously contemplated by domestic as well as international communities. This particle describes the physics of J-PARC-HI project as well as the current status.

Journal Articles

Interference effect between neutron direct and resonance capture reactions for neutron-rich nuclei

Minato, Futoshi; Fukui, Tokuro

EPJ Web of Conferences, 163, p.00037_1 - 00037_5, 2017/11

 Times Cited Count:1 Percentile:25.31

The capture reaction can be divided into two parts, that is the compound and direct processes. For most stable nuclei, the compound process occupies a large part of the neutron capture cross section. However, it has been pointed out that the direct process comes to play a comparable role to the compound one at a low energy in light and neutron-rich nuclei, where the number of resonance state at the neutron threshold energy is relatively small. In addition, there is an interference term between the direct and compound processes. However, it is usually neglected for most nuclei, because either of the compound or the direct process is more important than the other, its contribution becomes negligible. However, some experiment data have given an implication of the existence of the interference effect, and Mengoni and Otsuka reported that the experimental results of capture cross section can be described by taking into account it. It is then natural as a next step to have a concern whether the interference effect comes to play a role for neutron-rich nuclei as well. We therefore calculate the neutron capture reaction for neutron-rich nuclei and study the interference effect on it. We will present some results for neutron-rich nuclei and the interference effect becomes important.

Journal Articles

Study of fission using multi-nucleon transfer reactions

Nishio, Katsuhisa; Hirose, Kentaro; Vermeulen, M. J.; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Asai, Masato; Toyoshima, Atsushi; Sato, Tetsuya; Nagame, Yuichiro; et al.

EPJ Web of Conferences, 163, p.00041_1 - 00041_6, 2017/11

 Times Cited Count:1 Percentile:25.31

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:25.31

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

Neutron production in deuteron-induced reactions on Li, Be, and C at an incident energy of 102 MeV

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

EPJ Web of Conferences, 146, p.11027_1 - 11027_4, 2017/09

 Times Cited Count:0 Percentile:100

In recently years, deuteron-induced reaction is considered to produce the neutron source for application fields such as radiation damage fusion materials and boron neutron capture therapy. However, as the experimental data are not sufficient at incident energies above 60 MeV, the theoretical models are not validated. Therefore, we measured the double differential cross sections (DDXs) for Li, Be and C at 100 MeV at the Research Center for Nuclear Physics in Osaka University. The DDXs were measured at 6 angles (0$$^{circ}$$$$sim$$25$$^{circ}$$ and neutron energy was determined by a time of flight method. Three different-size NE213 liquid organic scintillators located at a distance of 7 m, 24 m and 74 m respectively were adopted as neutron detectors. In the measured DDXs, a broad peak due to deuteron breakup process was observed at approximately half of the deuteron incident energy. The DDXs calculated by PHITS did not reproduce the experimental ones due to lack of theoretical model.

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