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Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.
Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07
This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.
Kusano, Kanya*; Ichimoto, Kiyoshi*; Ishii, Mamoru*; Miyoshi, Yoshizumi*; Yoden, Shigeo*; Akiyoshi, Hideharu*; Asai, Ayumi*; Ebihara, Yusuke*; Fujiwara, Hitoshi*; Goto, Tadanori*; et al.
Earth, Planets and Space (Internet), 73(1), p.159_1 - 159_29, 2021/12
Times Cited Count：6 Percentile：51.19(Geosciences, Multidisciplinary)The PSTEP is a nationwide research collaboration in Japan and was conducted from April 2015 to March 2020, supported by a Grant-in-Aid for Scientific Research on Innovative Areas from the Ministry of Education, Culture, Sports, Science and Technology of Japan. It has made a significant progress in space weather research and operational forecasts, publishing over 500 refereed journal papers and organizing four international symposiums, various workshops and seminars, and summer school for graduate students at Rikubetsu in 2017. This paper is a summary report of the PSTEP and describes the major research achievements it produced.
and Fe
distribution in chevkinite-subgroup minerals; X-ray diffraction, neutron diffraction, 
Fe M
ssbauer spectroscopy and electron-microprobe analysesNagashima, Mariko*; Armbruster, T.*; Akasaka, Masahide*; Sano, Asami; Nishio-Hamane, Daisuke*; Malsy, A.*; Imaoka, Teruyoshi*; Nakashima, Kazuo*
Physics and Chemistry of Minerals, 47(6), p.29_1 - 29_18, 2020/06
Times Cited Count：3 Percentile：17.15(Materials Science, Multidisciplinary)Three non-metamict chevkinite-subgroup minerals, from Cape Ashizuri, Japan, Tangir Valley, Diamar District, Pakistan and Haramosh Mts., Skardu district, Pakistan, were studied by crystal chemical techniques. Powder X-ray diffraction and transmission electron microscopic observations confirmed well crystalline samples. Electron-microprobe analyses indicated the general composition known for chevkinite-(Ce). Site scattering values determined by single-crystal X-ray structure refinements suggested assignment of subordinate Nb to the octahedral M3 and M4 sites, minor Th to M1 for the Ashizuri sample and minor Mg to M1 for both samples from Pakistan. Neutron time-of-flight powder diffraction studies were applied to determine the Ti/Fe distribution among octahedral sites for all samples and Mossbauer spectroscopy served for the Fe valence assignment at the four octahedral sites. The dominant iron valence at M1 of the Haramosh sample is ferric whereas for samples Nos. 1 and 2 iron is ferrous.
Imazono, Takashi; Sano, Kazuo*; Koike, Masato
AIP Conference Proceedings 1465, p.28 - 32, 2012/07
Times Cited Count：1 Percentile：46.45(Physics, Applied)Imazono, Takashi; Moriya, Naoji*; Harada, Yoshihisa*; Sano, Kazuo*; Koike, Masato
AIP Conference Proceedings 1465, p.38 - 42, 2012/07
Times Cited Count：0 Percentile：0.13(Physics, Applied)Imazono, Takashi; Koike, Masato; Kawachi, Tetsuya; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; Sasai, Hiroyuki*; Oue, Yuki*; Yonezawa, Zeno*; Kuramoto, Satoshi*; et al.
Applied Optics, 51(13), p.2351 - 2360, 2012/05
Times Cited Count：12 Percentile：52.47(Optics)Laminar and blazed types holographic varied-line-spacing spherical gratings for use in a versatile soft X-ray flat-field spectrograph attached to an electron microscope are designed, fabricated, and evaluated. The absolute diffraction efficiencies of laminar (or blazed) master and replica gratings at 86.00
incidence evaluated by synchrotron radiation show over 5% (or 8%) in the 50-200 eV range with the maxima of 22% (or 26-27%). Also the resolving power evaluated by a laser produced plasma source is in excess of 700 at the energy near the 
emission spectrum of lithium (
55 eV) for all gratings. Moreover, the emission spectrum of metallic Li with high spectral resolution is successfully observed with the spectrograph attached to a transmission electron microscope.
emission spectrum of LiImazono, Takashi; Koike, Masato; Kawachi, Tetsuya; Hasegawa, Noboru; Koeda, Masaru*; Nagano, Tetsuya*; Sasai, Hiroyuki*; Oue, Yuki*; Yonezawa, Zeno*; Kuramoto, Satoshi*; et al.
Memoirs of the SR Center Ritsumeikan University, (14), p.131 - 144, 2012/05
We have developed a wavelength-dispersive soft X-ray spectrograph covering an energy region of 50-4000 eV to attach to a conventional electron microscope. The energy range was properly divided into four ranges of 50-200 eV, 155-350 eV, 300-2200 eV, and 2000-4000 eV, and a versatile spectrograph equipped with interchangeable multiple gratings optimized in the respective energy ranges has been developed. In particular, the grating that covers the 50-200 eV range can be used for the measurement of the emission spectrum ( 55 eV) of lithium. The diffraction efficiency evaluated by synchrotron radiation and resolving power measured by laser produced plasma sources are over 5% and in excess of 700, respectively. The emission spectrum of metallic Li with high spectral resolution has been successfully observed with the spectrograph attached to a transmission electron microscope.
Imazono, Takashi; Koike, Masato; Kawachi, Tetsuya; Koeda, Masaru*; Nagano, Tetsuya*; Sasai, Hiroyuki*; Oue, Yuki*; Yonezawa, Zeno*; Kuramoto, Satoshi*; Sano, Kazuo*
Proceedings of SPIE Europe Optics + Optoelectronics 2011, Vol.8139, p.81390V_1 - 81390V_9, 2011/09
Times Cited Count：3 Percentile：82.2(Optics)Ao, Hiroyuki; Asano, Hiroyuki; Tamura, Jun; Ouchi, Nobuo; Hasegawa, Kazuo; Morishita, Takatoshi; Takata, Koji*; Naito, Fujio*; Yamazaki, Yoshishige
Proceedings of 8th Annual Meeting of Particle Accelerator Society of Japan (Internet), 3 Pages, 2011/08
An annular-ring coupled structure (ACS) for J-PARC linac has been in mass-production since March 2009. It was planned to fabricate 18 ACS accelerating modules and two debuncher modules for the three years. At present, they are progressing on schedule. The past achievements include: ten accelerating modules were completed on schedule; the frequency tuning of the most accelerating modules was finished except two debencher modules; and 14 accelerating modules have been brazed. One of the mass-produced modules was conditioned up to 1.6 MW, which corresponds to the accelerating field by 15% higher than the designed value of 4.2 MV/m.
Imazono, Takashi; Sano, Kazuo*; Koike, Masato
Memoirs of the SR Center Ritsumeikan University, (13), p.145 - 156, 2011/06
Ao, Hiroyuki; Asano, Hiroyuki; Ouchi, Nobuo; Tsubota, Naoaki; Hasegawa, Kazuo; Hirano, Koichiro; Morishita, Takatoshi; Takata, Koji*; Naito, Fujio*; Yamazaki, Yoshishige
Proceedings of 7th Annual Meeting of Particle Accelerator Society of Japan (DVD-ROM), p.552 - 554, 2010/08
The energy upgrade of the J-PARC linac was started from March 2009. In this project 20 Annular Coupled Structure (ACS) modules will be fabricated. The resonant frequency of the ACS module has to be tuned with mechanical machining before the final brazing. Therefore the test cells were fabricated to accumulate frequency tuning parameters. We fixed the final dimensions and the machining amount of the frequency tuning using these results. So far, the cell parts for the five ACS modules were tuned within 71.93 
0.05 MHz. At the moment the first ACS module is being assembled and it will be completed in autumn 2010.
Imazono, Takashi; Sano, Kazuo*; Suzuki, Yoji; Kawachi, Tetsuya; Koike, Masato
AIP Conference Proceedings 1234, p.347 - 350, 2010/06
Times Cited Count：3 Percentile：75.85(Physics, Applied)Linear polarization measurements were carried out using a newly developed soft X-ray polarimeter and ellipsometer (SXPE) for complete polarization analysis at a soft X-ray beamline (BL-11) of the SR Center, Ritsumeikan University, Japan. A Mo/Si multilayer mirror was deposited on the surface of a Si(111) substrate by an ion beam sputtering method. It was cut into two pieces which were then used as reflection-type polarizers. When the incident wavelength was scanned from 12.4 nm to 14.8 nm by a Monk-Gillieson type varied-line-spacing grating monochromator of the BL-11, the angles of incidence of both the Mo/Si multilayer polarizers in the SXPE were also varied from 37.5 to 52.3. The polarizances depended strongly on the wavelength, and the best performance of over 99% was obtained in the vicinity of 14 nm. Using these polarizers, we assessed that the degree of linear polarization of the BL-11 was almost constant at 85-88% in the measured wavelength range.
Tanaka, Naritake*; Kimura, Hitoshi*; Faried, A.*; Sakai, Makoto*; Sano, Takaaki*; Inose, Takanori*; Soda, Makoto*; Okada, Koji*; Nakajima, Masanobu*; Miyazaki, Tatsuya*; et al.
Cancer Science, 101(6), p.1487 - 1492, 2010/06
Times Cited Count：12 Percentile：31.77(Oncology)We examined the intracellular localization of cisplatin, a key chemotherapeutic agent, in esophageal cancer cell lines and determined their sensitivity to cisplatin using in-air micro-PIXE. Two human esophageal squamous cell carcinoma (ESCC) cell lines, TE-2 and TE-13, were examined for their response to cisplatin using MTT assay, flow cytometry and DNA fragmentation assays. Real-time reverse transcription-polymerase chain reaction was also used to evaluate the mRNA expression of multidrug resistance protein 2 (MRP2) in both cell lines. Platinum localizations of intracellular and intranuclear were measured using in-air micro-PIXE. TE-2 cells were more sensitive to cisplatin than TE-13 cells. The results of this study suggest that in-air micro-PIXE could be a useful quantitative method for evaluating the cisplatin sensitivity of individual cells. Finally, we speculate that MRP2 in the cell membrane may play an important role in regulating cisplatin sensitivity of ESCC cells.
Imazono, Takashi; Sano, Kazuo*; Suzuki, Yoji; Kawachi, Tetsuya; Koike, Masato
Memoirs of the SR Center Ritsumeikan University, (12), p.87 - 100, 2010/05
A novel apparatus for polarimetric and ellipsometric measurements for the complete polarization analysis in the soft X-ray (SX) region, which is based on the rotating-analyzer ellipsometry by using six independently movable drive shafts, has been designed, constructed, and installed in BL-11. Linear polarization measurement has been demonstrated using two identical Mo/Si multilayer polarizers. The incident wavelength was scanned from 12.4 nm to 14.8 nm by a VLS-PGM of BL-11, and the angles of incidence of both polarizers were also varied from 37.5 to 52.3. The best performance of polarizers has been determined to be over 99% at 13.9 nm, and the degree of linear polarization has been assessed to be 85-88% in the measured wavelength range for the first time since the completion of the beamline. This means that BL-11 is upgraded as the comprehensive evaluation beamline for optical elements including polarizing elements for use in the SX region.
Ao, Hiroyuki; Asano, Hiroyuki; Ouchi, Nobuo; Tsubota, Naoaki; Hasegawa, Kazuo; Hirano, Koichiro; Morishita, Takatoshi; Takata, Koji*; Naito, Fujio*; Yamazaki, Yoshishige
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.618 - 620, 2010/05
The mass production of the ACS (Annular-ring Coupled Structure) cavity started from March 2009 for the J-PARC linac energy upgrade from 181 MeV to 400 MeV. This upgrade project requires 18 ACS accelerating modules and two debunchers additionally within three years. The schedule is so tight that we have to optimize the fabrication process. Thus the test cells were fabricated for the all geometrical beta before the mass production to confirm the initial design and the frequency tuning procedure. This paper describes our approach for the mass production and the current status.
Fang, Z.*; Michizono, Shinichiro*; Anami, Shozo*; Yamaguchi, Seiya*; Naito, Fujio*; Fukui, Yuji*; Kawamura, Masato*; Kubota, Chikashi*; Nammo, Kesao*; Kobayashi, Tetsuya; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.1434 - 1436, 2010/05
The output energy of the J-PARC proton linac will be upgraded from 181 to 400 MeV in the next two years by adding high-b acceleration sections. The upgrade of the FPGA-based digital LLRF controller for the 400 MeV linac will be presented in this paper. This new LLRF controller works for both the 324-MHz low-b and 972-MHz high-b sections. Many functions have been added into the LLRF controller, such as (1) working for different RF systems, (2) gradually increasing the feedback gains in the feedback loop instead of fixed ones, (3) automatic chopped beam compensation, (4) automatically switching the beam loading compensation in accordance with different beam operation mode, (5) input RF-frequency tuning to match the RF cavities during RF start-up, and (6) auto-tuning of the RF cavity tuner by detecting the phase curve of the RF cavity during the field decay instead of the phase difference between the cavity input and output signals.
Imazono, Takashi; Suzuki, Yoji; Sano, Kazuo*; Koike, Masato
Spectrochimica Acta, Part B, 65(2), p.147 - 151, 2010/02
Times Cited Count：2 Percentile：14.6(Spectroscopy)To meet the needs we have been developing an apparatus to evaluate polarization abilities of multilayer- and crystal-types polarizing elements and determine the polarization state of light in 1 keV region. The 8-axis goniometer called the polarization analysis-unit is equipped in this apparatus and consists of a phase shifter-unit and an analyzer-unit. All axes can be driven with HV compatible stepping motors. Both reflection- and transmission-types samples are available on P and A. Therefore, this apparatus makes it possible to carry out not only conventional reflection and transmission measurements but also four scanning modes which are double- reflections and transmissions, and transmission-reflection and vice versa.
Imazono, Takashi; Sano, Kazuo*; Suzuki, Yoji; Kawachi, Tetsuya; Koike, Masato
Review of Scientific Instruments, 80(8), p.085109_1 - 085109_8, 2009/08
Times Cited Count：18 Percentile：60.16(Instruments & Instrumentation)A new apparatus for polarimetric and ellipsometric measurements based on the rotating-analyzer method in the soft X-ray region has been designed, constructed, and installed in the soft X-ray beamline BL-11 at the SR Center of Ritsumeikan University, Shiga, Japan. It can realize the optical configurations for the complete polarization analysis by using six independently movable drive shafts. A demonstration of the capabilities of the apparatus has been performed using Mo/Si multilayer polarizers deposited by an ion beam sputtering method. It is for the first time shown that the degree of linear polarization of monochromatized light from the BL-11 is approximately 87% at 92 eV since the beamline has been constructed.
Koike, Masato; Ishino, Masahiko; Imazono, Takashi; Sano, Kazuo*; Sasai, Hiroyuki*; Hatayama, Masatoshi*; Takenaka, Hisataka*; Heimann, P. A.*; Gullikson, E. M.*
Spectrochimica Acta, Part B, 64(8), p.756 - 760, 2009/08
Times Cited Count：9 Percentile：42.95(Spectroscopy)W/C and Co/SiO
multilayer laminar-type holographic plane gratings (groove density 1/1200 lines /mm) in the 1-8 keV region are developed. For the Co/SiO grating the diffraction efficiencies of 0.41 and 0.47 at 4 and 6 keV, respectively, and for the W/C grating 0.38 at 8 keV are observed. Taking advantage of the outstanding high diffraction efficiencies into practical soft X-ray spectrographs a Mo/SiO multilayer varied-line-spacing (VLS) laminar-type spherical grating (1/2400 lines /mm) is also developed for use with a flat field spectrograph in the region of 1.7 keV. For the Mo/SiO multilayer grating the diffraction efficiencies of 0.05-0.20 at 0.9-1.8 keV are observed. The FWHM's of the measured line profiles of Hf-M
(1644.6 eV), Si-K (1740.0 eV),and W-M (1775.4 eV) are 13.7 eV, 8.0 eV, and 8.7 eV, respectively. It shows the validity of multilayer lamina-type gratings in the region.
Koike, Masato; Miyauchi, Shinji*; Sano, Kazuo*; Imazono, Takashi
Nanophotonics and Nanofabrication, p.179 - 191, 2009/05
Multilayer gratings having a groove density of 7600 lines/mm have been fabricated by depositing Mo/SiO multilayer coating on the surface of laminar-type master gratings fabricated by use of a new lithography machine based on optical near field technologies. The diffraction efficiency was measured by reflectometers in the wavelength range of 0.7 - 2.0 nm at a synchrotron radiation facility. The multilayer grating having a groove depth of 3 nm and multilayer period length of 5.33 nm showed diffraction efficiencies of 0.032 at 0.70 nm (1.77 keV) and 0.016 at 1.19 nm (1.04 keV) were observed for the incidence angles of 88.020 deg and 85.230 deg, respectively. We also discuss an analysis of the roughness in terms of Debye-Waller factor comparing the experimental and theoretical diffraction efficiencies.
