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Ishitsuka, Etsuo; Ho, H. Q.; Kitagawa, Kanta*; Fukuda, Takahito*; Ito, Ryo*; Nemoto, Masaya*; Kusunoki, Hayato*; Nomura, Takuro*; Nagase, Sota*; Hashimoto, Haruki*; et al.
JAEA-Technology 2023-013, 19 Pages, 2023/06
JAEA-Technology-2023-013.pdf:1.75MB
Eight people from five universities participated in the 2022 summer holiday practical training with the theme of "Technical development on HTTR". The participants practiced the feasibility study for nuclear battery, the burn-up analysis of HTTR core, the feasibility study for 
Cf production, the analysis of behavior on loss of forced cooling test, and the thermal-hydraulic analysis near reactor pressure vessel. In the questionnaire after this training, there were impressions such as that it was useful as a work experience, that some students found it useful for their own research, and that discussion with other university students was a good experience. These impressions suggest that this training was generally evaluated as good.
Okumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I.-H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.
IEEE Transactions on Applied Superconductivity, 31(5), p.2101704_1 - 2101704_4, 2021/08
Times Cited Count：1 Percentile：11.15(Engineering, Electrical & Electronic)A superconducting transition-edge sensor (TES) microcalorimeter is an ideal X-ray detector for experiments at accelerator facilities because of good energy resolution and high efficiency. To study the performance of the TES detector with a high-intensity pulsed charged-particle beam, we measured X-ray spectra with a pulsed muon beam at the Japan Proton Accelerator Research Complex (J-PARC) in Japan. We found substantial temporal shifts of the X-ray energy correlated with the arrival time of the pulsed muon beam, which was reasonably explained by pulse pileup due to the incidence of energetic particles from the initial pulsed beam.
X raysOkumura, Takuma*; Azuma, Toshiyuki*; Bennet, D. A.*; Caradonna, P.*; Chiu, I. H.*; Doriese, W. B.*; Durkin, M. S.*; Fowler, J. W.*; Gard, J. D.*; Hashimoto, Tadashi; et al.
Physical Review Letters, 127(5), p.053001_1 - 053001_7, 2021/07
Times Cited Count：13 Percentile：79.44(Physics, Multidisciplinary)We observed electronic X rays emitted from muonic iron atoms using a superconducting transition-edge-type sensor microcalorimeter. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic 
and 
X rays together with the hypersatellite X rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the 
-shell electrons, accompanied by electron side-feeding. Assisted by a simulation, this data clearly reveals the electronic - and -shell hole production and their temporal evolution during the muon cascade process.
Hayashi, Kenta; Nakamura, Takahisa; Takagi, Hisatsugu; Horie, Kaoru; Nakayama, Tamotsu; Hashimoto, Kazuhiko; Hayashi, Shoichi; Nakamura, Shinji; Takenaka, Shigeki; Ishizuka, Nobuo; et al.
Proceedings of INMM 54th Annual Meeting (CD-ROM), 10 Pages, 2013/07
JAEA and USDOE (Los Alamos National Laboratory (LANL)) have been collaborating on spent fuel measurements with a PNAR/SINRD NDA instrument at Fugen, in the course of the NGSI Spent Fuel Nondestructive Assay Project. In this collaboration, LANL's role has been to design and fabricate the detector (integrated PNAR and SINRD system), while JAEA's role has been to undertake the installation of the detector at the appropriate position in the spent fuel pool and to prepare for the actual measurements. In this paper we report the rehearsal of the measurement using a mock-up detector and a dummy fuel assembly in December 2012 and the plan of actual measurements in June 2013 (at the time of submission of this paper).
Fujii, Hirofumi*; Hara, Kazuhiko*; Hashimoto, Shugo*; Ito, Fumiaki*; Kakuno, Hidekazu*; Kim, S.*; Kochiyama, Mami; Nagamine, Kanetada*; Suzuki, Atsuto*; Takada, Yoshihisa*; et al.
Progress of Theoretical and Experimental Physics (Internet), 2013(7), p.073C01_1 - 073C01_20, 2013/07
Times Cited Count：26 Percentile：76.73(Physics, Multidisciplinary)Tsukada, Kazuaki; Haba, Hiromitsu*; Asai, Masato; Toyoshima, Atsushi; Akiyama, Kazuhiko*; Kasamatsu, Yoshitaka; Nishinaka, Ichiro; Ichikawa, Shinichi; Yasuda, Kenichiro; Miyamoto, Yutaka; et al.
Radiochimica Acta, 97(2), p.83 - 89, 2009/02
Times Cited Count：20 Percentile：77.78(Chemistry, Inorganic & Nuclear)Anion-exchange chromatography of element 105, dubnium (Db), produced in the 
Cm(
F, 5n)
Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K
) of Db on an anion-exchange resin is successfully determined by running cycles of the 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta 
Nb 
Db 
Pa.
Kawasuso, Atsuo; Fukaya, Yuki*; Hayashi, Kazuhiko; Hashimoto, Mie; Ichimiya, Ayahiko
Physica Status Solidi (C), 4(10), p.3924 - 3927, 2007/09
Well-focused and highly parallel positron beam is totally reflected at the first surface layer when grazing incidence at a small enough angles. Therefore, the reflection high-energy positron diffraction (RHEPD) is suited to determine the surface structures without any disturbance from the bulk. Using the electro-magnetic lenses we developed a positron beam which has more coherence than before. We found that the RHEPD pattern from the Si-7
7 surface is considerably different from that of electron diffraction. The difference is reasonably explained as a strong thermal diffuse scattering of positrons. As a further application, we studied the phase transition of Si-Ag ultra-thin film. We found that the surface-sensitive diffraction spots exhibit significant temperature dependences. Based on the dynamical diffraction theory, the temperature dependences are reproduced considering the order-disorder phase transition. This will terminate the long debates in the surface science community. Furthermore, we recently found that the positron-surface interaction is different from the electron-surface interaction, especially in the elastic processes. We present the above recent advances of surface studies using RHEPD.
Kawasuso, Atsuo; Fukaya, Yuki; Hayashi, Kazuhiko*; Hashimoto, Mie; Ichimiya, Ayahiko
Physica Status Solidi (C), 4(10), p.3924 - 3927, 2007/09
Times Cited Count：0 Percentile：0.07(Physics, Atomic, Molecular & Chemical)In this study, we performed the positron energy loss spectroscopy measurements from several surfaces using energy-filtered reflection high-energy positron diffraction. For Si(111)-77 surface, we observed at least five distinct loss peaks. The interval of energy loss peaks is approximately 10 eV, which corresponds to the surface plasmon loss energy of silicon. The positron energy loss spectra are well-approximated by the Poisson distribution. The average excitation number of surface plasmon is 2.6 under the total reflection condition. This number is similar to what expected for electrons at zero glancing angle. Thus, positrons lose their energy due to surface plasmon excitation much more sufficiently than electrons. We found that the specular spot is broadened in the total reflection region especially at the tail part due to plasmon excitation.
Sanada, Yukihisa; Kobayashi, Hirohide; Furuta, Sadaaki; Nemoto, Kazuhiko*; Kawai, Keiichi*; Hashimoto, Tetsuo*
Radioisotopes, 55(12), p.727 - 734, 2006/12
The purpose of this study is to develop new measurement methods of radon progenies that discharged alpha-ray focused on pulse time interval. It is calculated that a delayed coincidence method, time-interval-analysis (TIA), has been applied to decay events on the microsecond time-scale (164microsecond). The measurement system with silicon detectors was produced and examined a basic performance of the system by using 
Th electrodeposited sources. This system was designed that it have shorter dead times. The results were as follows. (1) The theory of measurement 
Po using TIA methods was established. (2) Development of the system that measured Po. (3) Suggested that methods to examine a basic performance by using Th electrodeposited sources. It is scheduled to examine the method of subtracting the progenies of the thorium series, and to reflect this system in an actual work of radiation control in the future.
-ray measurement methods with radon suppression focused on pulse time intervalSanada, Yukihisa; Nohara, Naofumi*; Adachi, Yasuyuki*; Nemoto, Kazuhiko*; Kawai, Keiichi*; Kobayashi, Hirohide; Hashimoto, Tetsuo*
JAEA-Technology 2005-009, 33 Pages, 2006/01
JAEA-Technology-2005-009.pdf:1.42MB
An -ray measurement methods based on analyzing the time interval of pulses was newly developed. This method was developed aiming to suppress the background counts originated in progeny of uranium series. A delayed coincidence and time interval analysis (TIA) methods have been applied to measure a-b decay successive events (correlated events) on microsecond time-scale (164
s). The measurement system have such functions with silicon detectors was developed intending to shorten the dead time. The basic performance of the system was examined by using Th electrodeposited sources. Follows were obtained in this work : The theory of measurement Po using TIA methods was established. Measurement system of Po was developed. Conformation methods of correlated events by using Th electrodeposited sources was suggested. The efficiency of correlated events in aerosol samples was estimated. The methods to measure correlated events was indicated by addition of Th. The method of subtracting the progenies of the thorium series are to examine.
Ohira, Shigeru; Tada, Eisuke; Hada, Kazuhiko; Neyatani, Yuzuru; Maruo, Takeshi; Hashimoto, Masayoshi*; Araki, Takao*; Nomoto, Kazuhiro*; Tsuru, Daigo; Ishida, Toshikatsu*; et al.
Fusion Science and Technology, 41(3), p.642 - 646, 2002/05
no abstracts in English
Tsuru, Daigo; Neyatani, Yuzuru; Araki, Takao*; Nomoto, Kazuhiro*; Ohira, Shigeru; Maruo, Takeshi; Hashimoto, Masayoshi*; Hada, Kazuhiko; Tada, Eisuke
Fusion Engineering and Design, 58-59, p.985 - 989, 2001/11
Times Cited Count：4 Percentile：33.39(Nuclear Science & Technology)no abstracts in English
Ohira, Shigeru; Tada, Eisuke; Hada, Kazuhiko; Neyatani, Yuzuru; Maruo, Takeshi; Hashimoto, Masayoshi*; Araki, Takao*; Nomoto, Kazuhiro*; Tsuru, Daigo; Ishida, Toshikatsu*; et al.
Fusion Engineering and Design, 54(3-4), p.515 - 522, 2001/04
Times Cited Count：3 Percentile：27.1(Nuclear Science & Technology)no abstracts in English
Hashimoto, Dai; Morimoto, Iwao; Zheng, X.; Maebara, Sunao; Nakajima, Mitsuo*; Horioka, Kazuhiko*; Kono, Toshiyuki*; Shiho, Makoto
JAERI-Research 2000-018, p.66 - 0, 2000/03
JAERI-Research-2000-018.pdf:2.19MB
no abstracts in English
Sanada, Yukihisa; Kobayashi, Hirohide; Nemoto, Kazuhiko*; Kawai, Keiichi*; Hashimoto, Tetsuo*
no journal, ,
no abstracts in English
Yamagishi, Akihiko*; Yokobori, Shinichi*; Hashimoto, Hirofumi*; Yano, Hajime*; Imai, Eiichi*; Okudaira, Kyoko*; Kawai, Hideyuki*; Kobayashi, Kensei*; Tabata, Makoto*; Nakagawa, Kazumichi*; et al.
no journal, ,
no abstracts in English
Harada, Masahide; Kawakami, Kazuhiro*; Aizawa, Kazuya; Soyama, Kazuhiko; Ishikado, Motoyuki*; Hiramatsu, Hideyuki*; Hashimoto, Norimichi*; Hosoya, Tomonori*; Ichimura, Katsuhiro*
no journal, ,
no abstracts in English
Harada, Masahide; Kawakami, Kazuhiro*; Aizawa, Kazuya; Soyama, Kazuhiko; Ishikado, Motoyuki*; Hiramatsu, Hideyuki*; Hashimoto, Norimichi*; Hosoya, Tomonori*; Ichimura, Katsuhiro*
no journal, ,
no abstracts in English
Hashimoto, Kazuhiko
no journal, ,
no abstracts in English
Hashimoto, Haruki*; Sawa, Kazuhiro*; Hasegawa, Toshinari; Nagasumi, Satoru; Ishitsuka, Etsuo; Iigaki, Kazuhiko
no journal, ,
no abstracts in English
