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Journal Articles

Reconstruction of residents' thyroid equivalent doses from internal radionuclides after the Fukushima Daiichi Nuclear Power Station accident

Oba, Takashi*; Ishikawa, Tetsuo*; Nagai, Haruyasu; Tokonami, Shinji*; Hasegawa, Arifumi*; Suzuki, Gen*

Scientific Reports (Internet), 10(1), p.3639_1 - 3639_11, 2020/02

 Times Cited Count:1 Percentile:24.98(Multidisciplinary Sciences)

Internal doses of residents after the Fukushima Daiichi Nuclear Power Station accident have been reconstructed. In total 896 behaviour records in the Fukushima Health Management Survey were analysed to estimate thyroid doses via inhalation, using a spatiotemporal radionuclides concentration database constructed by atmospheric dispersion simulations. After a decontamination factor for sheltering and a modifying factor for the dose coefficient were applied, estimated thyroid doses were close to those estimated on the basis of direct thyroid measurement. The median and 95th percentile of thyroid doses of 1-year-old children ranged from 1.2 to 15 mSv and from 7.5 to 30 mSv, respectively.

Journal Articles

Disk and washer coupled cavity linac design and cold-model for muon linac

Otani, Masashi*; Futatsukawa, Kenta*; Mibe, Tsutomu*; Naito, Fujio*; Hasegawa, Kazuo; Ito, Takashi; Kitamura, Ryo; Kondo, Yasuhiro; Morishita, Takatoshi; Iinuma, Hiromi*; et al.

Journal of Physics; Conference Series, 1350, p.012097_1 - 012097_7, 2019/12

 Times Cited Count:0 Percentile:100

A disk and washer (DAW) coupled cavity linac (CCL) has been developed for a middle velocity part in a muon linac to measure muon anomalous magnetic moment and search for electric dipole moment. I will accelerate muons from $$v/c$$ = $$beta$$ = 0.3 to 0.7 at an operational frequency of 1.3GHz. In this poster, the cavity design, beam dynamics design, and the cold-model measurements will be presented.

Journal Articles

Impacts of anthropogenic source from the nuclear fuel reprocessing plants on global atmospheric iodine-129 cycle; A Model analysis

Kadowaki, Masanao; Katata, Genki*; Terada, Hiroaki; Suzuki, Takashi; Hasegawa, Hidenao*; Akata, Naofumi*; Kakiuchi, Hideki*

Atmospheric Environment, 184, p.278 - 291, 2018/07

 Times Cited Count:6 Percentile:43.09(Environmental Sciences)

The long-lived radioactive iodine ($$^{129}$$I) is a useful geochemical tracer in the atmospheric environment. We recently observed clear seasonal trends in air concentration and deposition of $$^{129}$$I in Japan. Using these data, we developed a global atmospheric $$^{129}$$I transport model to reveal key processes for the global atmospheric $$^{129}$$I cycle. The model generally reproduced the observed seasonal change in air concentration and deposition of $$^{129}$$I in Japan, and the global distribution of $$^{129}$$I concentration in rain as presented in past literature. Numerical experiments changing the intensity of anthropogenic and natural sources were conducted to quantify the impact of anthropogenic sources on the global $$^{129}$$I cycle. The results indicated that the atmospheric $$^{129}$$I from the anthropogenic sources was deposited in winter and can be accumulated mainly in the northern part of Eurasia. In contrast, the atmospheric $$^{129}$$I from the natural sources dominated the deposition in summer. These results suggested that the re-emission process of $$^{129}$$I from the Earth's surface may be important as a secondary impact of $$^{129}$$I in the global-scaled environment. Furthermore, although wet deposition dominated the total deposition in the Northern hemisphere, dry deposition regionally and seasonally contributed to the total deposition over arctic and northern part of Eurasia in winter, suggesting that the dry deposition may play a key role in the seasonal change of $$^{129}$$I deposition in the Northern hemisphere high latitudes.

Journal Articles

The Muon linac for the precise measurement of muon g-2/EDM at J-PARC

Kondo, Yasuhiro; Hasegawa, Kazuo; Ito, Takashi; Artikova, S.; Otani, Masashi*; Mibe, Tsutomu*; Naito, Fujio*; Yoshida, Mitsuhiro*; Kitamura, Ryo*; Iwashita, Yoshihisa*; et al.

Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.66 - 69, 2016/11

We are developing a muon linac for the measurement of the muon anomalous magnetic moment and search for the muon electric dipole moment to explore beyond the Standard Model of elementary particle physics. This muon linac accelerate from room temperature to 212 MeV with normalized transverse emittances of about 1.5 $$pi$$ mm mrad. The muon linac consists of an ultra-slow muon source, a radio frequency quadrupole (RFQ) linac, an inter-digital H-mode drift tube linac (IH-DTL), a disk and washer coupled cavity linac (DAW CCL), and disk loaded structure (DLS) traveling-wave linac. In this paper, the status of the muon linac development, especially, the beam dynamics simulation is descried.

Journal Articles

Development of muon linac for the muon g-2/EDM experiment at J-PARC

Otani, Masashi*; Naito, Fujio*; Mibe, Tsutomu*; Yoshida, Mitsuhiro*; Hasegawa, Kazuo; Ito, Takashi; Kondo, Yasuhiro; Hayashizaki, Noriyosu*; Iwashita, Yoshihisa*; Iwata, Yoshiyuki*; et al.

Proceedings of 7th International Particle Accelerator Conference (IPAC '16) (Internet), p.1543 - 1546, 2016/06

We are developing a linac dedicated to the muon acceleration. It enables us to measure the muon anomalous magnetic moment with an accuracy of 0.1 ppm and search for electric dipole moment with a sensitivity of 10-21e cm to explore beyond Standard Model of elementary particle physics. As a first step for demonstration of the muon acceleration, we are developing the source of slow muon with which RFQ acceleration is conducted. This paper described status of these developments.

Journal Articles

Poly(ether ether ketone) (PEEK)-based graft-type polymer electrolyte membranes having high crystallinity for high conducting and mechanical properties under various humidified conditions

Hamada, Takashi; Hasegawa, Shin; Fukasawa, Hideyuki*; Sawada, Shinichi; Koshikawa, Hiroshi; Miyashita, Atsumi; Maekawa, Yasunari

Journal of Materials Chemistry A, 3(42), p.20983 - 20991, 2015/11

 Times Cited Count:20 Percentile:32.32(Chemistry, Physical)

no abstracts in English

JAEA Reports

Results of borehole investigation in -500m access/research gallery-north (13MI38$$sim$$13MI44 Boreholes)

Hasegawa, Takashi; Kawamoto, Koji; Yamada, Nobuto; Onuki, Kenji; Omori, Kazuaki; Takeuchi, Ryuji; Iwatsuki, Teruki; Sato, Toshinori

JAEA-Technology 2015-011, 135 Pages, 2015/07


The geological, hydraulic and geochemical data such as rock mass classification, groundwater inflow points and the volume, water pressure, and hydraulic conductivity were obtained from boreholes (13MI38$$sim$$13MI44) in the -500m Access/Research Gallery-North of Mizunami Underground Research laboratory (MIU). In addition to data acquisition, monitoring systems were installed to observe hydrochemical changes in the groundwater, and rock strain during and after the groundwater recovery experiment.

Journal Articles

On-site background measurements for the J-PARC E56 experiment; A Search for the sterile neutrino at J-PARC MLF

Ajimura, Shuhei*; Bezerra, T. J. C.*; Chauveau, E.*; Enomoto, T.*; Furuta, Hisataka*; Harada, Masahide; Hasegawa, Shoichi; Hiraiwa, T.*; Igarashi, Yoichi*; Iwai, Eito*; et al.

Progress of Theoretical and Experimental Physics (Internet), 2015(6), p.063C01_1 - 063C01_19, 2015/06

 Times Cited Count:2 Percentile:73.55(Physics, Multidisciplinary)

The J-PARC E56 experiment aims to search for sterile neutrinos at the J-PARC Materials and Life Science Experimental Facility (MLF). In order to examine the feasibility of the experiment, we measured the background rates of different detector candidate sites, which are located at the third floor of the MLF, using a detector consisting of plastic scintillators with a fiducial mass of 500 kg. The gammas and neutrons induced by the beam as well as the backgrounds from the cosmic rays were measured, and the results are described in this article.

JAEA Reports

Mizunami Underground Research Laboratory Project, Annual report for fiscal year 2013

Hama, Katsuhiro; Mikake, Shinichiro; Nishio, Kazuhisa; Kawamoto, Koji; Yamada, Nobuto; Ishibashi, Masayuki; Murakami, Hiroaki; Matsuoka, Toshiyuki; Sasao, Eiji; Sanada, Hiroyuki; et al.

JAEA-Review 2014-038, 137 Pages, 2014/12


Japan Atomic Energy Agency (JAEA) at Tono Geoscience Center (TGC) is pursuing a geoscientific research and development project namely the Mizunami Underground Research Laboratory (MIU) Project in crystalline rock environment in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste (HLW). The MIU Project has three overlapping phases: Surface-based Investigation phase (Phase I), Construction phase (Phase II), and Operation phase (Phase III). The MIU Project has been ongoing the Phase II and the Phase III in fiscal year 2013. This report presents the results of the investigations, construction and collaboration studies in fiscal year 2013, as a part of the Phase II and Phase III based on the MIU Master Plan updated in 2010.

JAEA Reports

Hydrochemical investigation at the Mizunami Underground Research Laboratory; Compilation of groundwater chemistry data in the Mizunami group and the Toki granite (fiscal year 2013)

Omori, Kazuaki; Hasegawa, Takashi; Munemoto, Takashi; Masuda, Kaoru*; Aosai, Daisuke*; Inui, Michiharu*; Iwatsuki, Teruki

JAEA-Data/Code 2014-019, 121 Pages, 2014/12


Japan Atomic Energy Agency has been investigating the groundwater chemistry on excavating the underground facilities as part of the Mizunami Underground research Laboratory (MIU) Project at Mizunami City, Gifu Prefecture, Japan. In this report, we compiled data obtained by geochemical research for groundwater at the MIU in the fiscal year 2013.

Journal Articles

Excitation spectrum of Josephson vortices on surface superconductor

Kawakami, Takuto*; Nagai, Yuki; Yoshizawa, Shunsuke*; Kim, H.*; Hasegawa, Yukio*; Nakayama, Tomonobu*; Uchihashi, Takashi*; Hu, X.*

Journal of Physics; Conference Series, 568(2), p.022022_1 - 022022_5, 2014/12

 Times Cited Count:1 Percentile:42.48

no abstracts in English

Journal Articles

Imaging Josephson vortices on the surface superconductor Si(111)-($$sqrt{7} times sqrt{3}$$)-In using a scanning tunneling microscope

Yoshizawa, Shunsuke*; Kim, H.*; Kawakami, Takuto*; Nagai, Yuki; Nakayama, Tomonobu*; Hu, X.*; Hasegawa, Yukio*; Uchihashi, Takashi*

Physical Review Letters, 113(24), p.247004_1 - 247004_5, 2014/12

 Times Cited Count:47 Percentile:7.87(Physics, Multidisciplinary)

We have studied the superconducting Si(111)-($$sqrt{7}$$$$times$$$$sqrt{3}$$)-In surface using a $$^{3}$$He-based low-temperature scanning tunneling microscope. Zero-bias conductance images taken over a large surface area reveal that vortices are trapped at atomic steps after magnetic fields are applied. The crossover behavior from Pearl to Josephson vortices is clearly identified from their elongated shapes along the steps and significant recovery of superconductivity within the cores. Our numerical calculations combined with experiments clarify that these characteristic features are determined by the relative strength of the interterrace Josephson coupling at the atomic step.

Journal Articles

Beam test of a new radio frequency quadrupole linac for the Japan Proton Accelerator Research Complex

Kondo, Yasuhiro; Morishita, Takatoshi; Yamazaki, Saishun; Hori, Toshihiko; Sawabe, Yuki; Chishiro, Etsuji; Fukuda, Shimpei; Hasegawa, Kazuo; Hirano, Koichiro; Kikuzawa, Nobuhiro; et al.

Physical Review Special Topics; Accelerators and Beams, 17(12), p.120101_1 - 120101_8, 2014/12

 Times Cited Count:5 Percentile:54.9(Physics, Nuclear)

We performed a beam test of a new radio frequency quadrupole linac (RFQ III) for the beam current upgrade of the Japan Proton Accelerator Research Complex. First, the conditioning of RFQ III was conducted, and after 20 h of conditioning, RFQ III became very stable with a nominal peak power and duty factor of 400 kW and 1.5%, respectively. An off-line beam test was subsequently conducted before installation in the accelerator tunnel. The transmission, transverse emittance, and energy spread of the 50-mA negative hydrogen beam from RFQ III were measured and compared with simulation results. The experiment and simulation results showed good agreement; therefore, we conclude that the performance of RFQ III conforms to its design.

Journal Articles

Present status of J-PARC linac

Oguri, Hidetomo; Hasegawa, Kazuo; Ito, Takashi; Chishiro, Etsuji; Hirano, Koichiro; Morishita, Takatoshi; Shinozaki, Shinichi; Ao, Hiroyuki; Okoshi, Kiyonori; Kondo, Yasuhiro; et al.

Proceedings of 11th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.389 - 393, 2014/10

no abstracts in English

JAEA Reports

Methodology development for colloid investigation in groundwater

Omori, Kazuaki; Munemoto, Takashi; Hasegawa, Takashi; Shingu, Shinya*; Hagiwara, Hiroki; Iwatsuki, Teruki

JAEA-Research 2014-013, 29 Pages, 2014/08


We summarized investigation method of colloid in groundwater. We examined the ultrafiltration of groundwater by using in-situ water monitoring system and batch type airtight container. Additionally, we examined the cross flow filtration method replaced by ultrafiltration. The knowledge of investigating methods is obtained.

Journal Articles

Exciting possibilities of soft X-ray emission spectroscopy as chemical state analysis in EPMA and FESEM

Takahashi, Hideyuki*; Handa, Nobuo*; Murano, Takanori*; Terauchi, Masami*; Koike, Masato; Kawachi, Tetsuya; Imazono, Takashi; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; et al.

Microscopy and Microanalysis, 20(Suppl.3), p.684 - 685, 2014/08

A novel wavelength dispersive soft X-ray emission spectrometer (SXES) having a X-ray energy range of 50-210 eV has been developed. One feature is that the SXES is parallel detection of the signals so that it can be used like a conventional energy dispersive spectrometer. The other is a high energy resolution, which is about 0.2 eV at Al-L comparable to those revealed by XPS and EELS. These features enable us to obtain meaningful information about chemical bonding in various bulk samples. The SXES can detect Li-K emission spectrum. In the case of an anode electrode of a lithium ion battery (LIB), two types of lithium peaks are observed: one lower energy peak at 50 eV and the other higher energy peak at 54 eV. It was found that the former peak corresponds to the amount of charging, whereas the latter corresponds to the metallic state of lithium.

Journal Articles

Small gas bubble experiment for mitigation of cavitation damage and pressure waves in short-pulse mercury spallation targets

Riemer, B. W.*; Wendel, M. W.*; Felde, D. K.*; Sangrey, R. L.*; Abdou, A.*; West, D. L.*; Shea, T. J.*; Hasegawa, Shoichi; Kogawa, Hiroyuki; Naoe, Takashi; et al.

Journal of Nuclear Materials, 450(1-3), p.192 - 203, 2014/07

 Times Cited Count:8 Percentile:34.41(Materials Science, Multidisciplinary)

Populations of small helium gas bubbles were introduced into a flowing mercury experiment test loop to evaluate mitigation of beam-pulse induced cavitation damage and pressure waves. The test loop was developed and thoroughly tested at the Spallation Neutron Source (SNS) prior to irradiations at the Los Alamos Neutron Science Center - Weapons Neutron Research Center (LANSCE-WNR) facility. Twelve candidate bubblers were evaluated over a range of mercury flow and gas injection rates by use of a novel optical measurement technique that accurately assessed the generated bubble size distributions. Final selection for irradiation testing included two variations of a swirl bubbler provided by Japan Proton Accelerator Research Complex (J-PARC) collaborators and one orifice bubbler developed at SNS. Bubble populations of interest consisted of sizes up to 150 $$mu$$m in radius with achieved gas void fractions in the 10$$^{-5}$$ to 10$$^{-4}$$ range. The nominal WNR beam pulse used for the experiment created energy deposition in the mercury comparable to SNS pulses operating at 2.5 MW. Nineteen test conditions were completed each with 100 pulses, including variations on mercury flow, gas injection and protons per pulse. The principal measure of cavitation damage mitigation was surface damage assessment on test specimens that were manually replaced for each test condition. Damage assessment was done after radiation decay and decontamination by optical and laser profiling microscopy with damaged area fraction and maximum pit depth being the more valued results. Damage was reduced by flow alone; the best mitigation from bubble injection was between half and a quarter that of flow alone. Other data collected included surface motion tracking by three laser Doppler vibrometers (LDV), loop wall dynamic strain, beam diagnostics for charge and beam profile assessment, embedded hydrophones and pressure sensors, and sound measurement by a suite of conventional and contact microphones.

Journal Articles

JT-60SA assembly and metrology

Suzuki, Sadaaki; Yagyu, Junichi; Masaki, Kei; Nishiyama, Tomokazu; Nakamura, Shigetoshi; Saeki, Hisashi; Hoshi, Ryo; Sawai, Hiroaki; Hasegawa, Koichi; Arai, Takashi; et al.

NIFS-MEMO-67, p.266 - 271, 2014/02

no abstracts in English

Journal Articles

Observation of the laser-induced surface dynamics using the single-shot soft X-ray laser probe

Hasegawa, Noboru; Ochi, Yoshihiro; Kawachi, Tetsuya; Nishikino, Masaharu; Ishino, Masahiko; Imazono, Takashi; Kaihori, Takeshi; Morita, Toshimasa; Sasaki, Akira; Terakawa, Kota*; et al.

X-Ray Lasers 2012; Springer Proceedings in Physics, Vol.147, p.117 - 120, 2014/00

 Times Cited Count:0 Percentile:100

We have developed the femto-second laser pump and soft X-ray laser probe system in order to observe the dynamical processes of the femto-second laser ablation. By using this system, we succeed to obtain the temporal evolution of the soft X-ray reflectivity from the laser induced Pt surface. The results lead that the rate of decrease in the reflectivity of the probe beam has a non-linear relation with the pump laser fluence.

JAEA Reports

Hydrogeochemical research and development at Mizunami Underground Research Laboratory up to 500m depth

Iwatsuki, Teruki; Yuguchi, Takashi; Omori, Kazuaki; Hasegawa, Takashi; Munemoto, Takashi

JAEA-Research 2013-021, 63 Pages, 2013/12


We evaluated the Phase I - hydrogeochemical model constructed by Surface-based investigation phase (Phase I), and observed hydrogeochemical change resulting from facility construction in Phase II research. Additionally we developed investigation technique on redox condition, colloid/organics, etc. at gallery in Phase III research. Hydrogeochemical changes in sedimentary rocks and granite resulting from facility construction have been caused by the change of mixing ratio among salinity-distinct groundwaters. Multivariate numerical analysis shows that the groundwater chemistry around drifts would change to that of shallow groundwater in the future. The know-hows on hydrochemical monitoring at the hydrogeological structures and numerical analysis were summarized to infer the hydrochemical changing processes during the facility construction.

245 (Records 1-20 displayed on this page)