Measurement of double-differential neutron yields for iron, lead, and bismuth induced by 107-MeV protons for research and development of accelerator-driven systems

Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Sugihara, Kenta*; Nishio, Katsuhisa; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; et al.

EPJ Web of Conferences, 284, p.01023_1 - 01023_4, 2023/05

https://doi.org/10.1051/epjconf/202328401023

For accurate prediction of neutronic characteristics for accelerator-driven systems (ADS) and a source term of spallation neutrons for reactor physics experiments for the ADS at Kyoto University Critical Assembly (KUCA), we have launched an experimental program to measure nuclear data on ADS using the Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University. As part of this program, the proton-induced double-differential thick-target neutron-yields (TTNYs) and cross-sections (DDXs) for iron, lead, and bismuth have been measured with the time-of-flight (TOF) method. For each measurement, the target was installed in a vacuum chamber on the beamline and bombarded with 107-MeV proton beams accelerated from the FFAG accelerator. Neutrons produced from the targets were detected with stacked, small-sized neutron detectors for several angles from the incident beam direction. The TOF spectra were obtained from the detected signals and the FFAG kicker magnet's logic signals, where gamma-ray events were eliminated by pulse shape discrimination. Finally, the TTNYs and DDXs were obtained from the TOF spectra by relativistic kinematics. The measured TTNYs and DDXs were compared with calculations by the Monte Carlo transport code PHITS with its default physics model of INCL version 4.6 combined with GEM and those with the JENDL-4.0/HE nuclear data library.

Measurement of 107-MeV proton-induced double-differential thick target neutron yields for Fe, Pb, and Bi using a fixed-field alternating gradient accelerator at Kyoto University

Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Sugihara, Kenta; Nishio, Katsuhisa; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; et al.

Journal of Nuclear Science and Technology, 60(4), p.435 - 449, 2023/04

https://doi.org/10.1080/00223131.2022.2115423

Double-differential thick target neutron yields (TTNYs) for Fe, Pb, and Bi targets induced by 107-MeV protons were measured using the fixed-field alternating gradient accelerator at Kyoto University for research and development of accelerator-driven systems (ADSs) and fundamental ADS reactor physics research at the Kyoto University Critical Assembly (KUCA). Note that TTNYs were obtained with the time-of-flight method using a neutron detector system comprising eight neutron detectors; each detector has a small NE213 liquid organic scintillator and photomultiplier tube. The TTNYs obtained were compared with calculation results using Monte Carlo-based spallation models (i.e., INCL4.6/GEM, Bertini/GEM, JQMD/GEM, and JQMD/SMM/GEM) and the evaluated high-energy nuclear data library, i.e., JENDL-4.0/HE, implemented in the particle and heavy iontransport code system (PHITS). All models, including JENDL-4.0/HE, failed to predict high-energy peaks at a detector angle of 5. Comparing the energy- and angle-integrated spallation neutron yields at energies of 20 MeV estimated using the measured TTNYs and the PHITS indicated that INCL4.6/GEM would be suitable for the Monte Carlo transport simulation of ADS reactor physics experiments at the KUCA.

Measurement of 107-MeV proton-induced double-differential neutron yields for iron for research and development of accelerator-driven systems

Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; Yashima, Hiroshi*; Nishio, Katsuhisa; et al.

JAEA-Conf 2022-001, p.129 - 133, 2022/11

https://doi.org/10.11484/jaea-conf-2022-001

For accurate prediction of neutronic characteristics for accelerator-driven systems (ADS) and a source term of spallation neutrons for reactor physics experiments for the ADS at Kyoto University Critical Assembly (KUCA), we have launched an experimental program to measure nuclear data on ADS using the Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University. As part of this program, the proton-induced double-differential thick-target neutron-yields (TTNYs) and cross-sections (DDXs) for iron have been measured with the time-of-flight (TOF) method. For each measurement, the target was installed in a vacuum chamber on the beamline and bombarded with 107-MeV proton beams accelerated from the FFAG accelerator. Neutrons produced from the targets were detected with stacked, small-sized neutron detectors composed of the NE213 liquid organic scintillators and photomultiplier tubes, which were connected to a multi-channel digitizer mounted with a field-programmable gate array (FPGA), for several angles from the incident beam direction. The TOF spectra were obtained from the detected signals and the FFAG kicker magnet's logic signals, where gamma-ray events were eliminated by pulse shape discrimination applying the gate integration method to the FPGA. Finally, the TTNYs and DDXs were obtained from the TOF spectra by relativistic kinematics.

Development of dissolved hydrogen concentration control apparatus by solid polymer electrolyte water electrolysis method

Nakano, Hiroko; Fuyushima, Takumi; Tsuguchi, Akira*; Nakamura, Mutsumi*; Takeuchi, Tomoaki; Takemoto, Noriyuki; Ide, Hiroshi

JAEA-Technology 2022-007, 34 Pages, 2022/06

JAEA-Technology-2022-007.pdf:3.35MB

In order to investigate the phenomenon of stress corrosion cracking (SCC) for structural materials at the light water reactor (LWR), it is important to manage a water quality for simulating high-temperature and high-pressure water. Generally, dissolved hydrogen (DH) concentration in water loop has been controlled by the bubbling method of pure hydrogen gas or standard gas with high hydrogen concentration. However, it is necessary to equip the preventing hydrogen explosion in the area installed experimental apparatus. In general, in order to prevent accident by hydrogen, it is required to take measures such as limiting the amount of leakage, eliminating hydrogen, shutting off the power supply, and suppressing combustion before an explosion occurs. Thus, the dissolved hydrogen concentration control apparatus by electrolysis method has been developed which has two electrolysis cells to control DH concentration by electrolyzing water loop. In this study, small basic experimental devices were set up. The preliminary data were acquired regarding the simple performance of two electrolysis cells and the change of DH concentration in circulation. Based on the preliminary data, the dissolved hydrogen concentration control apparatus was designed to be connected to the high-temperature and high-pressure water loop test equipment. This report describes the test results with the small basic experimental devices for the design of the dissolved hydrogen concentration control apparatus.

Development of the treatment method for difficult wastes aimed at decommissioning of JMTR; Structural materials of reactor and used ion-exchange resins

Seki, Misaki; Nakano, Hiroko; Nagata, Hiroshi; Otsuka, Kaoru; Omori, Takazumi; Takeuchi, Tomoaki; Ide, Hiroshi; Tsuchiya, Kunihiko

Dekomisshoningu Giho, (62), p.9 - 19, 2020/09

Japan Materials Testing Reactor (JMTR) has been contributing to various research and development activities such as the fundamental research of nuclear materials/fuels, safety research and development of power reactors, and radioisotope production since the beginning of the operation in 1968. JMTR, however, was decided as a one of decommission facilities in April 2017 and it is taken an inspection of a plan concerning decommissioning because the performance of JMTR does not confirm with the stipulated earthquake resistance. As aluminum and beryllium are used for the core structural materials in JMTR, it is necessary to establish treatment methods of these materials for the fabrication of stable wastes. In addition, a treatment method for the accumulated spent ion-exchange resins needs to be examined. This report describes the overview of these examination situations.

Spallation and fragmentation cross sections for 168 MeV/nucleon 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

https://doi.org/10.1103/PhysRevC.101.064623

The spallation and fragmentation reactions of 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.

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

https://doi.org/10.1038/s42005-019-0165-1

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.

High-temperature oxidation of sheath materials using mineral-insulated cables for a simulated severe accident

Nakano, Hiroko; Hirota, Noriaki; Shibata, Hiroshi; Takeuchi, Tomoaki; Tsuchiya, Kunihiko

Mechanical Engineering Journal (Internet), 5(2), p.17-00594_1 - 17-00594_12, 2018/04

https://doi.org/10.1299/mej.17-00594

no abstracts in English

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

https://doi.org/10.1051/epjconf/201714611027

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 (025 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.

Measurement of double differential (d,xn) cross sections for carbon at an incident energy of 100 MeV

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

JAEA-Conf 2016-004, p.159 - 164, 2016/09

https://doi.org/10.11484/jaea-conf-2016-004

Neutron production data from materials such as Li, Be and C bombarded by deuteron are required for design such as the facility of radiation damage for fusion materials and boron neutron capture therapy. However, there is little measurement of double differential neutron production cross sections (DDXs). Therefore, we have planned a series of DDXs measurements at incident energies more than 100 MeV in the Research Center for Nuclear Physics, Osaka University. The experiment was carried out with a carbon target at the neutron Time of Flight (TOF) course in RCNP. Emitted neutrons were detected by three different-size NE213 liquid organic scintillators (5.08 cm, 12.7 cm and 25.4 cm in dimeter and thickness) located at a distance of 7 m, 24 m and 74 m respectively. The neutron detection efficiencies of the detectors were calculated by SCINFUL-QMD code. It turned out that the calculation data fr carbon does not reproduce the experimental data satisfactorily well.