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 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.

Radioactivity and radionuclides in deciduous teeth formed before the Fukushima-Daiichi Nuclear Power Plant accident

Takahashi, Atsushi*; Chiba, Mirei*; Tanahara, Akira*; Aida, Jun*; Shimizu, Yoshinaka*; Suzuki, Toshihiko*; Murakami, Shinobu*; Koarai, Kazuma; Ono, Takumi*; Oka, Toshitaka; et al.

Scientific Reports (Internet), 11(1), p.10355_1 - 10355_11, 2021/05

https://doi.org/10.1038/s41598-021-89910-0

Role of multichance fission in the description of fission-fragment mass distributions at high energies

Hirose, Kentaro; Nishio, Katsuhisa; Tanaka, Shoya*; Lguillon, R.*; Makii, Hiroyuki; Nishinaka, Ichiro*; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Vermeulen, M. J.; et al.

Physical Review Letters, 119(22), p.222501_1 - 222501_6, 2017/12

https://doi.org/10.1103/PhysRevLett.119.222501

Fission-fragment mass distributions were measured for U, Np and Pu populated in the excitation-energy range from 10 to 60 MeV by multi-nucleon transfer channels in the reaction O + U at the JAEA tandem facility. Among them, the data for U and Np were observed for the first time. It was found that the mass distributions for all the studied nuclides maintain a double-humped shape up to the highest measured energy in contrast to expectations of predominantly symmetric fission due to the washing out of nuclear shell effects. From a comparison with the dynamical calculation based on the fluctuation-dissipation model, this behavior of the mass distributions was unambiguously attributed to the effect of multi-chance fission.

High-pressure and high-temperature experiments using multi-anvil appratus; Recent results

Funakoshi, Kenichi*; Utsumi, Wataru; Otaka, Osamu*; Irifune, Tetsuo*; Inoue, Toru*; Ito, Eiji*; Katsura, Tomoo*; Kubo, Atsushi*; Hirose, Kei*; Ando, Junichi*; et al.

Ganseki Kobutsu Kagaku, 30(2), p.102 - 103, 2001/03

https://doi.org/10.2465/gkk.30.102

no abstracts in English

Measurement of neutron energy spectra from Fe target using FFAG proton accelerator

Nakano, Keita; Iwamoto, Hiroki; Meigo, Shinichiro; Nishio, Katsuhisa; Ishi, Yoshihiro*; Hirose, Kentaro; Iwamoto, Yosuke; Kuriyama, Yasutoshi*; Maekawa, Fujio; Makii, Hiroyuki; et al.

no journal, , 

For accurate prediction of neutronic characteristics for accelerator-driven system (ADS), an experimental program to measure nuclear data on ADS using the Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University has been launched. As a part of this program, energy spectra of spallation neutron from 100-MeV proton-induced reactions on Fe, Pb, and Bi are plan to be measured. In this report, the results of the measurement on Fe target will be presented.

Measurement and analysis of 107-MeV proton-induced neutron yields for iron, lead and bismuth

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

no journal, , 

For the purpose of research and development of accelerator-driven nuclear transmutation systems, neutron yields of 107-MeV proton incident on iron, lead and bismuth targets were measured by the flight time method using the FFAG accelerator at Kyoto University. The energy spectra of the neutron yield obtained by the measurements were compared with results of particle transport analysis with the nuclear reaction models (INCL4.6/GEM, Bertini/GEM, JQMD/GEM and JQMD/SMM/GEM) incorporated in the Monte Carlo particle transport calculation code PHITS and the nuclear data library JENDL-4.0/HE. As a result, it was found that the INCL4.6/GEM, which was the reference model of PHITS, best reproduced the experimental values.