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Journal Articles

Rabi-oscillation spectroscopy of the hyperfine structure of muonium atoms

Nishimura, Shoichiro*; Torii, Hiroyuki*; Fukao, Yoshinori*; Ito, Takashi; Iwasaki, Masahiko*; Kanda, Sotaro*; Kawagoe, Kiyotomo*; Kawall, D.*; Kawamura, Naritoshi*; Kurosawa, Noriyuki*; et al.

Physical Review A, 104(2), p.L020801_1 - L020801_6, 2021/08

 Times Cited Count:0

Journal Articles

Study on cooling process in a reactor vessel of sodium-cooled fast reactor under severe accident; Velocity measurement experiments simulating operation of decay heat removal systems

Tsuji, Mitsuyo; Aizawa, Kosuke; Kobayashi, Jun; Kurihara, Akikazu; Miyake, Yasuhiro*

Proceedings of 2020 International Conference on Nuclear Engineering (ICONE 2020) (Internet), 5 Pages, 2020/08

The water experiments using a 1/10 scale experimental apparatus simulating the reactor vessel of SFR were conducted to investigate the natural circulation phenomena in a reactor vessel. In this paper, the natural circulation flow field in the reactor vessel was measured by the Particle Image Velocimetry (PIV) method. The PIV measurement was carried out under the operation of the dipped-type direct heat exchanger (DHX) installed in the upper plenum when 20% of the core fuel fell to the lower plenum and accumulated on the core catcher. From the results of PIV measurement, it was quantitatively confirmed that the upward flow occurred at the center region of the lower and upper plenums. In addition, the downward flows were confirmed near the reactor vessel wall in the upper plenum and through outermost layer of the simulated core in the lower plenum. Moreover, the relationship between the temperature field and the velocity field was investigated in order to understand the natural circulation phenomenon in the reactor vessel. From the above results, it was confirmed that the natural circulation cooling path was established under the dipped-type DHX operation.

Journal Articles

Preliminary analysis of sodium experimental apparatus PLANDTL-2 for development of evaluation method for thermal-hydraulics in reactor vessel of sodium fast reactor under decay heat removal system operation condition

Ono, Ayako; Tanaka, Masaaki; Miyake, Yasuhiro*; Hamase, Erina; Ezure, Toshiki

Mechanical Engineering Journal (Internet), 7(3), p.19-00546_1 - 19-00546_11, 2020/06

Fully natural circulation decay heat removal systems (DHRSs) are to be adopted for sodium fast reactors, which is a passive safety feature without any electrical pumps. It is required to grasp the thermal-hydraulic phenomena in the reactor vessel and evaluate the coolability of the core under the natural circulation not only for the normal operating condition but also for severe accident conditions. In this paper, the numerical results of the preliminary analysis for the sodium experimental condition with the PLANDTL-2 are discussed to establish an appropriate numerical models for the reactor core including the gap region among the subassemblies and the DHX. From these preliminary analyses, the characteristics of the thermal-hydraulics behavior in the PLANDTL-2 to be focused are extracted.

Journal Articles

Impact of hydrided and non-hydrided materials near transistors on neutron-induced single event upsets

Abe, Shinichiro; Sato, Tatsuhiko; Kuroda, Junya*; Manabe, Seiya*; Watanabe, Yukinobu*; Liao, W.*; Ito, Kojiro*; Hashimoto, Masanori*; Harada, Masahide; Oikawa, Kenichi; et al.

Proceedings of IEEE International Reliability Physics Symposium (IRPS 2020) (Internet), 6 Pages, 2020/04

Single event upsets (SEUs) caused by neutrons have been recognized as a serious reliability problem for microelectronic devices on the ground level. In our previous work, it was found that hydride placed in front of the memory chip has considerably impact on SEU cross sections because H ions generated via elastic scattering of neutrons with hydrogen atoms are only emitted in a forward direction. In this study, the effect of components neighboring transistors on neutron-induced SEUs was investigated for 65-nm bulk SRAMs by using PHITS. It was found that the shape of the SEU cross section around few MeV comes from the thickness and the position of components placed in front of transistors when that components do not contains hydrogen atoms. By considering components adjoin memory cells in the test board used in the simulation, measured data at J-PARC BL10 were reproduced well. In addition, it was found that the effect of components neighboring transistors on neutron-induced SERs does not negligible in terrestrial environment.

Journal Articles

Negative muonium ion production with a C12A7 electride film

Otani, Masashi*; Fukao, Yoshinori*; Futatsukawa, Kenta*; Kawamura, Naritoshi*; Matoba, Shiro*; Mibe, Tsutomu*; Miyake, Yasuhiro*; Shimomura, Koichiro*; Yamazaki, Takayuki*; Hasegawa, Kazuo; et al.

Journal of Physics; Conference Series, 1350, p.012067_1 - 012067_6, 2019/12

 Times Cited Count:0 Percentile:0.07

Negative muonium atom ($$mu^+$$e$$^-$$e$$^-$$, Mu$$^-$$) has unique features stimulating potential interesting for several scientific fields. Since its discovery in late 1980's in vacuum, it has been discussed that the production efficiency would be improved using a low-work function material. C12A7 was a well-known insulator as a constituent of alumina cement, but was recently confirmed to exhibit electric conductivity by electron doping. The C12A7 electride has relatively low-work function (2.9 eV). In this paper, the negative muonium production measurement with several materials including a C12A7 electride film will be presented. Measured production rate of the Mu$$^-$$ were 10$$^{-3}$$/s for all the Al, electride, and SUS target. Significant enhancement on electride target was not observed, thus it is presumed that the surface condition should be more carefully treated. There was no material dependence of the Mu$$^-$$ averaged energy: it was 0.2$$pm$$0.1keV.

Journal Articles

Preliminary analysis of sodium experimental apparatus PLANDTL-2 for development of evaluation method for thermal hydraulics in reactor vessel of sodium fast reactor under decay heat removal system operation condition

Ono, Ayako; Tanaka, Masaaki; Miyake, Yasuhiro*; Hamase, Erina; Ezure, Toshiki

Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 7 Pages, 2019/05

Decay heat removal system (DHRS) by using the natural circulation without depending on the pump as the mechanical equipment is recognized as one of the most effective methodologies for the sodium-cooled fast reactor from the viewpoint of the safety enhancement. In this paper, the numerical simulation results of the preliminary analysis for the sodium experiment with the apparatus of PLANDTL-2, in which the core and the upper plenum with a dipped-type direct heat exchanger (DHX) were modeled, were discussed, in order to establish appropriate numerical models for the reactor core including the gap region among the subassemblies and the DHX.

Journal Articles

Negative and positive muon-induced single event upsets in 65-nm UTBB SOI SRAMs

Manabe, Seiya*; Watanabe, Yukinobu*; Liao, W.*; Hashimoto, Masanori*; Nakano, Keita*; Sato, Hikaru*; Kin, Tadahiro*; Abe, Shinichiro; Hamada, Koji*; Tampo, Motonobu*; et al.

IEEE Transactions on Nuclear Science, 65(8), p.1742 - 1749, 2018/08

 Times Cited Count:5 Percentile:65.87(Engineering, Electrical & Electronic)

Recently, the malfunction of microelectronics caused by secondary cosmic-ray muon is concerned as semiconductor devices become sensitive to radiation. In this study, we have performed muon irradiation testing for 65-nm ultra-thin body and thin buried oxide (UTBB-SOI) SRAMs in the Japan Proton Accelerator Research Complex (J-PARC), in order to investigate dependencies of single event upset (SEU) cross section on incident muon momentum and supply voltage. It was found that the SEU cross section by negative muon are approximately two to four times larger than those by positive muon in the momentum range from 35 MeV/c to 39 MeV/c. The supply voltage dependence of muon-induced SEU cross section was measured with the momentum of 38 MeV/c. SEU cross sections decrease with increasing supply voltage, but the decreasing of SEU cross section by negative muon is gentler than that by positive muon. Experimental data of positive and negative muon irradiation with the momentum of 38 MeV/c were analyzed by PHITS. It was clarified that the negative muon capture causes the difference between the SEU cross section by negative muon and that by positive muon.

Journal Articles

Measurement and mechanism investigation of negative and positive muon-induced upsets in 65-nm Bulk SRAMs

Liao, W.*; Hashimoto, Masanori*; Manabe, Seiya*; Watanabe, Yukinobu*; Abe, Shinichiro; Nakano, Keita*; Sato, Hikaru*; Kin, Tadahiro*; Hamada, Koji*; Tampo, Motonobu*; et al.

IEEE Transactions on Nuclear Science, 65(8), p.1734 - 1741, 2018/08

 Times Cited Count:12 Percentile:91.7(Engineering, Electrical & Electronic)

Soft error induced by secondary cosmic-ray muon is concerned since susceptibility of semiconductor device to soft error increases with the scaling of technology. In this study, we have performed irradiation tests of muons on 65-nm bulk CMOS SRAM in the Japan Proton Accelerator Research Complex (J-PARC) and measured soft error rate (SER) to investigate mechanism of muon-induced soft errors. It was found that SER by negative muon increases above 0.5 V supply voltage, although SER by positive muon increases monotonically as the supply voltage lowers. SER by negative muon also increases with forward body bias. In addition, negative muon causes large multiple cell upset (MCU) of more than 20 bits and the ratio of MCU events to all the events is 66% at 1.2V supply voltage. These tendencies indicate that parasitic bipolar action (PBA) is highly possible to contribute to SER by negative muon. Experimental data are analyzed by PHITS. It was found that negative muon can deposit larger charge than positive muon, and such events that can deposit large charge may trigger PBA.

Journal Articles

Development of numerical estimation method for thermal hydraulics in reactor vessel of sodium-cooled fast reactor under decay heat removal system operation conditions; Preliminary thermal hydraulics simulation for simulated reactor vessel in sodium experimental apparatus PLANDTL-2

Tanaka, Masaaki; Ono, Ayako; Hamase, Erina; Ezure, Toshiki; Miyake, Yasuhiro*

Nihon Kikai Gakkai Kanto Shibu Ibaraki Koenkai 2018 Koen Rombunshu (CD-ROM), 4 Pages, 2018/08

Decay heat removal system (DHRS) by using the natural circulation without depending on the pump as the mechanical equipment is recognized as one of the most effective methodologies for the sodium-cooled fast reactor from the viewpoint of the safety enhancement. The numerical estimation method which can predict thermal hydraulic phenomena in the natural circulation under the plant cooling process by operating the various DHRSs including the severe accident is necessarily required. In this paper, the numerical results of the preliminary analysis for the sodium experiment condition with the apparatus of PLANDTL-2, in which the core and the upper plenum with a dipped-type direct heat exchanger (DHX) were modeled, were discussed, in order to establish an appropriate numerical models for the direct heat exchanger (DHX).

Journal Articles

First muon acceleration using a radio-frequency accelerator

Bae, S.*; Choi, H.*; Choi, S.*; Fukao, Yoshinori*; Futatsukawa, Kenta*; Hasegawa, Kazuo; Iijima, Toru*; Iinuma, Hiromi*; Ishida, Katsuhiko*; Kawamura, Naritoshi*; et al.

Physical Review Accelerators and Beams (Internet), 21(5), p.050101_1 - 050101_6, 2018/05

 Times Cited Count:11 Percentile:82.39(Physics, Nuclear)

Muons have been accelerated by using a radio-frequency accelerator for the first time. Negative muonium atoms (Mu$$^{-}$$), which are bound states of positive muons and two electrons, are generated from through the electron capture process in an aluminum degrader. The generated Mu$$^{-}$$'s are initially electrostatically accelerated and injected into a radio-frequency quadrupole linac (RFQ). In the RFQ, the Mu$$^{-}$$'s are accelerated to 89 keV. The accelerated Mu$$^{-}$$'s are identified by momentum measurement and time of flight. This compact muon linac opens the door to various muon accelerator applications including particle physics measurements and the construction of a transmission muon microscope.

Journal Articles

New precise measurement of muonium hyperfine structure interval at J-PARC

Ueno, Yasuhiro*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Keiichi*; Ito, Takashi; Iwasaki, Masahiko*; et al.

Hyperfine Interactions, 238(1), p.14_1 - 14_6, 2017/11

 Times Cited Count:3 Percentile:91.22

Journal Articles

First trial of the muon acceleration for J-PARC muon g-2/EDM experiment

Kitamura, Ryo*; Otani, Masashi*; Fukao, Yoshinori*; Kawamura, Naritoshi*; Mibe, Tsutomu*; Miyake, Yasuhiro*; Shimomura, Koichiro*; Kondo, Yasuhiro; Hasegawa, Kazuo; Bae, S.*; et al.

Proceedings of 8th International Particle Accelerator Conference (IPAC '17) (Internet), p.2311 - 2313, 2017/06

Muon acceleration is an important technique in exploring the new frontier of physics. A new measurement of the muon dipole moments is planned in J-PARC using the muon linear accelerator. The low-energy (LE) muon source using the thin metal foil target and beam diagnostic system were developed for the world's first muon acceleration. Negative muonium ions from the thin metal foil target as the LE muon source was successfully observed. Also the beam profile of the LE positive muon was measured by the LE-dedicated beam profile monitor. The muon acceleration test using a Radio-Frequency Quadrupole linac (RFQ) is being prepared as the first step of the muon accelerator development. In this paper, the latest status of the first muon acceleration test is described.

Journal Articles

Materials and Life Science Experimental Facility at the Japan Proton Accelerator Research Complex, 4; The Muon Facility

Higemoto, Wataru; Kadono, Ryosuke*; Kawamura, Naritoshi*; Koda, Akihiro*; Kojima, Kenji*; Makimura, Shunsuke*; Matoba, Shiro*; Miyake, Yasuhiro*; Shimomura, Koichiro*; Strasser, P.*

Quantum Beam Science (Internet), 1(1), p.11_1 - 11_24, 2017/06

A muon experimental facility, known as the Muon Science Establishment (MUSE), is one of the user facilities at the Japan Proton Accelerator Research Complex, along with those for neutrons, hadrons, and neutrinos. The MUSE facility is integrated into the Materials and Life Science Facility building in which a high-energy proton beam that is shared with a neutron experiment facility delivers a variety of muon beams for research covering diverse scientific fields. In this review, we present the current status of MUSE, which is still in the process of being developed into its fully fledged form.

Journal Articles

Muon acceleration using an RFQ

Kondo, Yasuhiro; Hasegawa, Kazuo; Otani, Masashi*; Mibe, Tsutomu*; Fukao, Yoshinori*; Kawamura, Naritoshi*; Miyake, Yasuhiro*; Shimomura, Koichiro*; Kitamura, Ryo*; Ishida, Katsuhiko*; et al.

Proceedings of 28th International Linear Accelerator Conference (LINAC 2016) (Internet), p.992 - 995, 2017/05

The muon linear accelerator for the muon g-2/EDM experiment in J-PARC is being developed. As the first step of the muon acceleration, the muon acceleration with J-PARC RFQ (Radio-Frequency Quadrupole)-II plans to be demonstrated at H-line of J-PARC MLF. The slow muon will be obtained by the deceleration using the thin metal foil target in the RFQ acceleration test. The intensity of the decelerated muon by the thin metal foil was measured. Based on this result, the beam intensity in the RFQ test at H-line is estimated to be a few /sec. The particle simulation of the RFQ and the following beam diagnostics system is conducted, and it is shown that the emittance measurement at the RFQ exit using the micro-channel plate based beam profile monitor is feasible.

Journal Articles

Study on reactor vessel coolability of sodium-cooled fast reactor under severe accident condition; Water experiments using a scale model

Ono, Ayako; Kurihara, Akikazu; Tanaka, Masaaki; Ohshima, Hiroyuki; Kamide, Hideki; Miyake, Yasuhiro*; Ito, Masami*; Nakane, Shigeru*

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 10 Pages, 2017/04

The water experiment apparatus simulating the thermal hydraulics in a reactor vessel under operating the decay heat removal systems (DHRSs) was fabricated. The theoretical evaluation for similarity and results of basic experiments show applicability for a scale model experiment of a sodium-cooled fast reactor. This paper, moreover, describes the results of flow visualization experiment under operating a dipped-type passive DHX, which is planned to be installed in both a loop type reactor and pool type reactor, and the calculation results using FLUENT comparing with the result of water experiment.

Journal Articles

New muonium HFS measurements at J-PARC/MUSE

Strasser, P.*; Aoki, Masaharu*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Keiichi*; Ito, Takashi; Iwasaki, Masahiko*; et al.

Hyperfine Interactions, 237(1), p.124_1 - 124_9, 2016/12

 Times Cited Count:6 Percentile:93.01

Journal Articles

Current status of the muon initial acceleration with RFQ for muon g-2/EDM experiment

Kitamura, Ryo*; Otani, Masashi*; Fukao, Yoshinori*; Kawamura, Naritoshi*; Mibe, Tsutomu*; Miyake, Yasuhiro*; Shimomura, Koichiro*; Kondo, Yasuhiro; Hasegawa, Kazuo; Ishida, Katsuhiko*; et al.

Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.476 - 479, 2016/11

The muon linear accelerator for the muon g-2/EDM experiment in J-PARC is being developed. As the first step of the muon acceleration, the muon acceleration with J-PARC RFQ (Radio-Frequency Quadrupole)-II plans to be demonstrated at H-line of J-PARC MLF. The slow muon will be obtained by the deceleration using the thin metal foil target in the RFQ acceleration test. The intensity of the decelerated muon by the thin metal foil was measured. Based on this result, the beam intensity in the RFQ test at H-line is estimated to be a few /sec. The particle simulation of the RFQ and the following beam diagnostics system is conducted, and it is shown that the emittance measurement at the RFQ exit using the micro-channel plate based beam profile monitor is feasible.

Journal Articles

A Study on the thermal-hydraulics in the damaged subassemblies under the operation of decay heat removal system

Ono, Ayako; Onojima, Takamitsu; Doda, Norihiro; Miyake, Yasuhiro*; Kamide, Hideki

Proceedings of 2016 International Congress on Advances in Nuclear Power Plants (ICAPP 2016) (CD-ROM), p.2183 - 2192, 2016/04

Some auxiliary cooling systems to remove the decay heat of the core are under consideration for a sodium-cooled fast reactor, and two of the typical systems are primary reactor auxiliary cooling system (PRACS) and direct reactor auxiliary cooling system (DRACS). In this study, sodium experiments were conducted in order to confirm the applicability of the PRACS and DRACS under a situation assuming the severe accidents with core melting. The plant dynamics test loop was used for these experiments, which contains a simulated core, the PRACS and DRACS. The core melt situation is simulated by shutting off the inlet of subassemblies (S/A). The experimental results revealed the cooling process of the partially/completely inactive S/A and confirmed the long-term heat removal by the PRACS/DRACS.

Journal Articles

Development of numerical estimation method for high cycle thermal fatigue by coupling of fluid-structure thermal interaction simulation and thermal stress analysis

Tanaka, Masaaki; Miyake, Yasuhiro*

Nihon Kikai Gakkai M&M 2015 Zairyo Rikigaku Kanfarensu Koen Rombunshu (Internet), 3 Pages, 2015/11

A prototype coupling method consisting of the fluid-structure thermal interaction simulation code MUGTHES and the structural thermal stress analysis code FINAS with interface program MUFIN has been developed in order to estimate the thermal fatigue in the SFRs. As a fundamental validation of the coupled method, it was applied to the water experiment for thermal mixing phenomena in a T-junction piping system. In the experiment, thermal interaction between the fluid and the structure made of aluminum installed to the branch pipe side wall was considered. Through the numerical simulations, applicability of the coupled method was confirmed.

Journal Articles

Numerical simulation of thermal striping phenomena in a T-junction piping system for fundamental validation and uncertainty quantification by GCI estimation

Tanaka, Masaaki; Miyake, Yasuhiro*

Mechanical Engineering Journal (Internet), 2(5), p.15-00134_1 - 15-00134_20, 2015/10

In this study, numerical simulation for the water experiment of a T-junction piping system (T-pipe) was carried out to validate the MUGTHES and to investigate the relation between the mechanism of temperature fluctuation generation and the unsteady motion of large eddy structures. In the numerical simulation, the large eddy simulation (LES) approach with standard Smagorinsky model was employed as eddy viscosity model to simulate large scale eddy motion in the T-pipe. As for uncertainty quantification in the validation process, the modified method of the Grid Convergence Index (GCI) estimation based on the least squire version could successfully quantify uncertainty. Through the numerical simulations, it could be found that the thermal mixing phenomena in the T-pipe were caused by the mutual interaction of the necklace-shaped vortex around the wake from the front of the branch jet, the horseshoe-shaped vortex and the Karman's vortex motions in the wake.

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