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Karube, Kosuke*; Onuki, Yoshichika*; Nakajima, Taro*; Chen, H.-Y.*; Ishizuka, Hiroaki*; Kimata, Motoi*; Ohara, Takashi; Munakata, Koji*; Nomoto, Takuya*; Arita, Ryotaro*; et al.
npj Quantum Materials (Internet), 10, p.55_1 - 55_9, 2025/06
Times Cited Count：8 Percentile：89.66(Materials Science, Multidisciplinary)Thennakoon, A.*; Yokokura, Ryoga*; Yang, Y.*; Kajimoto, Ryoichi; Nakamura, Mitsutaka; Hayashi, Masahiro*; Michioka, Chishiro*; Chern, G.-W.*; Broholm, C.*; Ueda, Hiroaki*; et al.
Nature Communications (Internet), 16, p.3939_1 - 3939_13, 2025/04
Times Cited Count：4 Percentile：68.00(Multidisciplinary Sciences)
-FeNi films with island structures on LaAlO
(110) substrates by nitrogen insertion and topotactic extractionNishio, Takahiro*; Ito, Keita*; Kura, Hiroaki*; Takanashi, Koki; Yanagihara, Hideto*
Journal of Alloys and Compounds, 976, p.172992_1 - 172992_8, 2024/03
Times Cited Count：3 Percentile：18.38(Chemistry, Physical)
Tamii, Atsushi*; Pellegri, L.*; S
derstrm, P.-A.*; Allard, D.*; Goriely, S.*; Inakura, Tsunenori*; Khan, E.*; Kido, Eiji*; Kimura, Masaaki*; Litvinova, E.*; et al.
European Physical Journal A, 59(9), p.208_1 - 208_21, 2023/09
Times Cited Count：22 Percentile：94.07(Physics, Nuclear)no abstracts in English
layers in the triple-layer cuprate BiSrCaCu
O
studied by angle-resolved photoemission spectroscopyIdeta, Shinichiro*; Johnston, S.*; Yoshida, Teppei*; Tanaka, Kiyohisa*; Mori, Michiyasu; Anzai, Hiroaki*; Ino, Akihiro*; Arita, Masashi*; Namatame, Hirofumi*; Taniguchi, Masaki*; et al.
Physical Review Letters, 127(21), p.217004_1 - 217004_6, 2021/11
Times Cited Count：20 Percentile：74.52(Physics, Multidisciplinary)
dosimetry system based on an optical fiber-coupled microsized photostimulable phosphor for stereotactic body radiation therapyYada, Ryuichi*; Maenaka, Kazusuke*; Miyamoto, Shuji*; Okada, Go*; Sasakura, Aki*; Ashida, Motoi*; Adachi, Masashi*; Sato, Tatsuhiko; Wang, T.*; Akasaka, Hiroaki*; et al.
Medical Physics, 47(10), p.5235 - 5249, 2020/10
Times Cited Count：10 Percentile：46.74(Radiology, Nuclear Medicine & Medical Imaging)The dosimeter system is capable of real-time, accurate, and precise measurement under stereotactic body radiation therapy (SBRT) conditions. The probe is smaller than a conventional dosimeter, has excellent spatial resolution, and can be valuable in SBRT with a steep dose distribution over a small field. The developed PSP dosimeter system appears to be suitable for in vivo SBRT dosimetry.
Naito, Fujio*; Anami, Shozo*; Ikegami, Kiyoshi*; Uota, Masahiko*; Ouchi, Toshikatsu*; Onishi, Takahiro*; Oba, Toshiyuki*; Obina, Takashi*; Kawamura, Masato*; Kumada, Hiroaki*; et al.
Proceedings of 13th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1244 - 1246, 2016/11
The proton linac installed in the Ibaraki Neutron Medical Research Center is used for production of the intense neutron flux for the Boron Neutron Capture Therapy (BNCT). The linac consists of the 3-MeV RFQ and the 8-MeV DTL. Design average beam current is 10mA. Target is made of Beryllium. First neutron production from the Beryllium target was observed at the end of 2015 with the low intensity beam as a demonstration. After the observation of neutron production, a lot of improvement s was carried out in order to increase the proton beam intensity for the real beam commissioning. The beam commissioning has been started on May 2016. The status of the commissioning is summarized in this report.
pellets for (n, 
) 
Mo productionNishikata, Kaori; Kimura, Akihiro; Tsuchiya, Kunihiko; Suzuki, Kunihiko*; Akiyama, Hiroaki*; Nagakura, Masaaki*; Kawauchi, Yukimasa*; Tanase, Masakazu*
Proceedings of 5th International Symposium on Material Testing Reactors (ISMTR-5) (Internet), 9 Pages, 2012/10
In this study, experimental fabrication tests of the high-density MoO pellets were carried out by the Plasma Activated Sintering (PAS) method, which requires relatively lower temperature and shorter time to fabricate the pellets. From the results, the PAS method combined with oxidation process, prior to dissolution into sodium hydroxide solution, is a useful measure to fabricate high-density MoO Pellets for the future domestic production of 
Tc. The irradiation tests and characterization with these pellets will be carried out under the international cooperation.
imaging device of high spatial resolution ZnO scintillatorNakazato, Tomoharu*; Shimizu, Toshihiko*; Yamanoi, Kohei*; Sakai, Kohei*; Takeda, Kohei*; Nishi, Ryosuke*; Minami, Yuki*; Cadatal-Raduban, M.*; Sarukura, Nobuhiko*; Nishimura, Hiroaki*; et al.
Japanese Journal of Applied Physics, 50(12), p.122202_1 - 122202_4, 2011/12
Times Cited Count：11 Percentile：38.56(Physics, Applied)We demonstrate the potential of a hydrothermal method-grown ZnO as a high-spatial resolution imaging device for in-situ soft X-ray laser diagnostics by characterizing the exciton emission patterns. By plotting the emission pattern radii at each position, we estimated the evolution of the beam radius around the focal point. The beam profile of the Ni-like Ag ion plasma laser was estimated from the waist radii as 29 and 21
m, the divergence angle as 7.2 and 11 mrad and the M2 factor as 47 and 50 in the horizontal- and vertical-axis, respectively. Spatial resolution of the magnifier was estimated to be 6m and is expected to improve by optimizing the optics of the magnifier and using a telescope. Our results would enhance the use of ZnO as an imaging device that would play a crucial role in the development and application of soft X-ray light sources.
Kawachi, Tetsuya; Hasegawa, Noboru; Nishikino, Masaharu; Ishino, Masahiko; Imazono, Takashi; Oba, Toshiyuki; Kaihori, Takeshi; Kishimoto, Maki; Ochi, Yoshihiro; Tanaka, Momoko; et al.
X-Ray Lasers 2010; Springer Proceedings in Physics, Vol.136, p.15 - 24, 2011/12
This paper reviews recent improvement in the source development of laser-driven X-ray lasers and the applications in the research fields of material science, laser processing, X-ray imaging, and radiation damage in biological cells. In the application for material science, we have firstly observed temporal correlation between the domain structures of ferro-electric substance under the Curie temperature. In the laser processing, new X-ray laser interferometer reveals us the nano-scale surface distortion of substance pumped by a femto-second optical pulse. In the X-ray diffraction image, we have taken several static images of micro-structure of samples: now we are trying to extend the objective to nano-scale dynamics using pump and probe method. In the radiation damage of biological cells, we observed double strand break in DNA using X-ray laser exposure; this results are compared with the case using incoherent several KeV X-ray exposure.
Terada, Atsuhiko; Takegami, Hiroaki; Noguchi, Hiroki; Kamiji, Yu; Ishikura, Shuichi*
Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 6 Pages, 2011/10
The Japan Atomic Energy Agency has been conducting study on thermo-chemical Iodine-Sulfur (IS) process for water splitting hydrogen production. In design of the IS test equipment, it is important to design ceramics chemical reactors with high performance from the viewpoint of thermal hydraulics and structural integrity. A new simple hydraulic analytical code has been developed for considering sulfuric acid solution as a mixture of two components especially in the HSO
decomposer. Complex flow with liquid-vaporized interaction involving chemical reaction will be characterized in the HSO decomposer. Based on the preliminary analytical results obtained with above mentioned code, conceptual investigation of structural integrity of ceramics decomposer was carried out by a general commercial FEM code.
Kiyanagi, Yoshiaki*; Kino, Koichi*; Furusaka, Michihiro*; Hiraga, Fujio*; Kamiyama, Takashi*; Kato, Kiyoshi*; Igashira, Masayuki*; Katabuchi, Tatsuya*; Mizumoto, Motoharu*; Oshima, Masumi; et al.
Journal of the Korean Physical Society, 59(2), p.1781 - 1784, 2011/08
Times Cited Count：13 Percentile：60.13(Physics, Multidisciplinary)The project of the comprehensive nuclear data research for the development of the advanced reactor systems had been executed successfully by eight organizations from 2005 to 2009. In this project, we constructed the pulsed neutron beamline that was aimed to obtain neutron capture cross-sections of long-lived fission products and minor actinides accurately. The energy spectra, spatial distributions, and pulses of the beam were studied by measurements and simulation calculations, and they were found to be consistent with those of the beamline design. In this paper, we present the overview of the project and the properties of the neutron beam provided by this beam line.
Uchida, Shunsuke; Asakura, Yamato*; Suzuki, Hiroaki*
Nuclear Engineering and Design, 241(7), p.2398 - 2410, 2011/07
Times Cited Count：41 Percentile：92.47(Nuclear Science & Technology)In PWR, it has been assumed that Li and B ions deposited on fuel under sub-cooled boiling conditions. Accumulated B on the fuel led to AOA. The amount of B deposited on the fuel was evaluated from two directions. The first calculated the amount with the extended MED model and the other estimated it from the viewpoint of reactor reactivity. It was concluded that: (1) the calculated B deposition amount on the fuel, which was one or two orders larger than measured amounts and Ni oxides compounds, was seldom measured in the fuel deposits due to its high release rate; (2) its hideout return during the reactor shutdown period was seldom observed due to its high concentration in the primary coolant; (3) one of the most promising approaches to evaluate its accumulation on the fuel during plant operation was the MED model calculation; and (4) control of Ni concentration in the primary coolant resulted in decreased Ni oxide deposition and then mitigation of AOA occurrence.
Takegami, Hiroaki; Ishikura, Shuichi*; Terada, Atsuhiko; Inagaki, Yoshiyuki
JAEA-Technology 2011-002, 41 Pages, 2011/03
JAEA-Technology-2011-002.pdf:5.08MB
The IS process is the hydrogen production method which used the thermochemical reaction cycle of sulfuric acid and iodyne. The sulfuric acid decomposer, which is one of the important equipment of the IS process, is the equipment to heat with hot helium and for the sulfuric acid of 90 wt% to evaporate. The heat exchanger is required to be pressure-resistant structure because it uses high-pressure helium of 4 MPa, and the material is required to have heat resistance and corrosion resistance with high temperature sulfuric acid more than 700 
C. Therefore, silicon carbide (SiC) was selected from the corrosion experiment as the most excellent material. However, the structure design technique of ceramics structures is not serviced as the standard. In this report, the structural design technique was studied by the material strength characteristic of the ceramics into consideration.
Nakazato, Tomoharu*; Furukawa, Yusuke*; Tanaka, Momoko; Tatsumi, Toshihiro*; Nishikino, Masaharu; Yamatani, Hiroshi*; Nagashima, Keisuke; Kimura, Toyoaki*; Murakami, Hidetoshi*; Saito, Shigeki*; et al.
Journal of Crystal Growth, 311(3), p.875 - 877, 2009/01
Times Cited Count：25 Percentile：85.72(Crystallography)The temperature dependence of scintillation properties of a hydrothermal-method-grown zinc oxide (ZnO) emission is investigated using a nickel-like silver laser emitting at 13.9 nm. A broad peak at 386 nm with a full-width at half-maximum (FWHM) of 15 nm at room temperature (298 K) is obtained. The peak position tends to be blue shifted while the FWHM becomes narrower when the crystal temperature is decreased to 25 K. Streak images fitted by a double exponential decay reveal that the measured emission decay at 105 K was 
= 0.88 ns and = 2.7 ns. This decay time of a few nanoseconds is suitable for lithographic applications and is sufficiently short for the characterization of laser plasma extreme ultraviolet (EUV) sources with nanosecond durations.
Tanaka, Momoko; Furukawa, Yusuke*; Nakazato, Tomoharu*; Tatsumi, Toshihiro*; Murakami, Hidetoshi*; Shimizu, Toshihiko*; Sarukura, Nobuhiko*; Nishikino, Masaharu; Kawachi, Tetsuya; Kagamitani, Yuji*; et al.
X-Ray Lasers 2008; Springer Proceedings in Physics, Vol.130, p.501 - 505, 2009/00
We measured the time-resolved fluorescence spectra of ZnO and GaN single crystals excited by an X-ray laser operating at 13.9 nm and evaluated their scintillation properties for EUV excitation as compared with UV excitation case. For ZnO, a clear fluorescence peak of excitonic origin was observed at around 380 nm and the decay lifetime of less than 3 ns is found to be almost similar to the UV excitation case. The fluorescence at 380 nm is ideal for scintillator device design in the EUV and further applications. For GaN, the lifetimes are much longer than ZnO and the temporal profile of the EUV-excited fluorescence differs with the UV excitation case. As such, the EUV scintillation properties of ZnO is said to be more favorable than GaN. Finally, it is also demonstrated that an X-ray laser is an excellent tool for spectroscopic characterization of materials intended for next-generation lithography applications.
Furukawa, Yusuke*; Tanaka, Momoko; Murakami, Hidetoshi*; Saito, Shigeki*; Sarukura, Nobuhiko*; Nishikino, Masaharu; Yamatani, Hiroshi; Nishimura, Hiroaki*; Mima, Kunioki*; Kagamitani, Yuji*; et al.
Reza Kenkyu, 36(APLS), p.1028 - 1030, 2008/12
Optical technologies in extreme ultraviolet (EUV) region have been receiving strong interests for the next generation lithography. Here we report properties of ZnO as scintillators in the EUV region, and to demonstrate the feasibility of using a Ni-like Ag EUV laser operated at 13.9-nm to evaluate these properties. The ZnO sample was irradiated with EUV laser pulses and the fluorescence was measured using a streak camera fitted with a spectrograph. A clear, excitonic, fluorescence peak was observed at around 380 nm with a decay lifetime of 3 ns. The prominent peak fluorescence is ideal for EUV detection and further applications including imaging.
Furukawa, Yusuke*; Tanaka, Momoko; Nakazato, Tomoharu*; Tatsumi, Toshihiro*; Nishikino, Masaharu; Yamatani, Hiroshi; Nagashima, Keisuke; Kimura, Toyoaki; Murakami, Hidetoshi*; Saito, Shigeki*; et al.
Journal of the Optical Society of America B, 25(7), p.B118 - B121, 2008/07
Times Cited Count：27 Percentile：73.82(Optics)Using EUV laser operated at 13.9 nm ZnO and GaN are shown to be excellent scintillators in this wavelength region. Especially ZnO has short response time of 3 ns and prominent peak fluorescence from excitation at 380 nm.
Tanaka, Momoko; Furukawa, Hiroyuki*; Murakami, Hidetoshi*; Saito, Shigeki*; Sarukura, Nobuhiko*; Nishikino, Masaharu; Yamatani, Hiroshi; Nagashima, Keisuke; Kagamitani, Yuji*; Ehrentraut, D.*; et al.
Journal of Physics; Conference Series, 112(4), p.042058_1 - 042058_4, 2008/00
Times Cited Count：1 Percentile：52.77(Physics, Fluids & Plasmas)Optical technologies in the extreme ultraviolet (EUV) region have been receiving strong interest for the next generation lithography. Efficient and fast scintillators are one of the key devices functioning in the EUV region. In this paper, we report excellent properties of ZnO and GaN as scintillators in the EUV region, and to demonstrate the feasibility of using a Ni-like Ag EUV laser operated at 13.9-nm to evaluate these properties. The sample was irradiated with EUV laser pulses, and the fluorescence spectrum and the fluorescence lifetime were measured using a streak camera fitted with a spectrograph. In the case of ZnO, a clear, excitonic, fluorescence peak was observed at around 380 nm with a decay lifetime of 3 ns. For GaN, a fluorescence peak at 370 nm having slower 5-ns decay time was observed. In this respect, the EUV scintillation properties of ZnO is said to be more favorable than GaN.
Tanaka, Momoko; Nishikino, Masaharu; Yamatani, Hiroshi; Nagashima, Keisuke; Kimura, Toyoaki; Furukawa, Yusuke*; Murakami, Hidetoshi*; Saito, Shigeki*; Sarukura, Nobuhiko*; Nishimura, Hiroaki*; et al.
Applied Physics Letters, 91(23), p.231117_1 - 231117_3, 2007/12
Times Cited Count：55 Percentile：84.46(Physics, Applied)The scintillation properties of a hydrothermal method grown zinc oxide (ZnO) crystal are evaluated for extreme ultraviolet (EUV) laser excitation at 13.9 nm wavelength. The exciton emission lifetime at around 380 nm is determined to be 1.1 ns, almost identical to ultraviolet laser excitation cases. This fast response time is sufficiently short for characterizing EUV lithography light sources having a few nanoseconds duration. The availability of large size ZnO crystal up to 3-inch is quite attractive for future lithography and imaging applications.
