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Imazono, Takashi; Sano, Kazuo*; Koike, Masato
AIP Conference Proceedings 1465, p.28 - 32, 2012/07
Times Cited Count:1 Percentile:46.55Imazono, Takashi; Moriya, Naoji*; Harada, Yoshihisa*; Sano, Kazuo*; Koike, Masato
AIP Conference Proceedings 1465, p.38 - 42, 2012/07
Times Cited Count:0 Percentile:0.13Imazono, 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:52.6(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.
Imazono, 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:2 Percentile:82.27Imazono, Takashi; Sano, Kazuo*; Koike, Masato
Memoirs of the SR Center Ritsumeikan University, (13), p.145 - 156, 2011/06
Imazono, Takashi; Sano, Kazuo*; Suzuki, Yoji; Kawachi, Tetsuya; Koike, Masato
AIP Conference Proceedings 1234, p.347 - 350, 2010/06
Times Cited Count:3 Percentile:75.92Linear 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.
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.
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:60.25(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:43.04(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.
Ishino, Masahiko; Koike, Masato; Sato, Futami*; Terauchi, Masami*; Sano, Kazuo*; Sasai, Hiroyuki*
Journal of Applied Physics, 104(7), p.073520_1 - 073520_5, 2008/10
Times Cited Count:0 Percentile:0(Physics, Applied)The multilayer gratings were fabricated by depositing the Co/Si and Co/SiO multilayers onto the surface of laminar-type holographic gratings having shallow grooves. The structures of multilayer gratings observed by a transmission electron microscope showed the well defined structures without serious defects. The structural property evaluated by comparing the measured and calculated diffraction conditions i.e., incidence and diffraction angles, resulted that the diffraction conditions of multilayer gratings were affected by the refractive indices of multilayer coatings even at the photon energy of 8.05 keV. The measured low diffraction efficiencies for the Co/Si multilayer grating in the photon energy range of 1-2 keV would be attributed to the large inter-diffusion in the Co/Si multilayer coating.
Koike, Masato; Imazono, Takashi; Kawazoe, Tadashi*; Otsu, Motoichi*; Sano, Kazuo*
Denki Gakkai Hikari, Ryoshi Debaisu Kenkyukai Shiryo OQD-08-34, p.15 - 18, 2008/05
A Mo/SiO multilayer laminar-type holographic grating having an average groove density of 2400 lines/mm is designed and fabricated for use with a soft X-ray flat field spectrograph. A varied-line-spaced grooves pattern is generated by the use of an aspheric wavefront recording system and laminar-type grooves are formed by a reactive ion-etching method. The measured first-order diffraction efficiency is 1820%. The flat field spectrograph equipped with the grating indicates a spectral line width of 814 eV for the emission spectra generated from electron-impact X-ray sources. A Mo/SiO multilayer grating having a groove density of 7600 lines/mm fabricated by use of a new lithography machine based on optical near field technologies showed first-order diffraction efficiency of 3%. It is over one order magnitude higher than that of the other orders.
Ishino, Masahiko; Koike, Masato; Sano, Kazuo*
Memoirs of the SR Center Ritsumeikan University, (10), p.131 - 137, 2008/05
no abstracts in English
Imazono, Takashi; Ishino, Masahiko; Koike, Masato; Sasai, Hiroyuki*; Sano, Kazuo*
Memoirs of the SR Center Ritsumeikan University, (10), p.119 - 130, 2008/05
A multilayer laminar-type holographic grating having an average groove density of 2400 lines/mm is designed and fabricated for use with a soft X-ray flat field spectrograph covering the 1.7-keV region. A varied-line-spaced grooves pattern is generated by the use of an aspheric wavefront recording system and laminar-type grooves are formed by a reactive ion-etching method. Mo/SiO multilayers optimized for the emission lines of Hf-M, Si-K, and W-M are deposited on one of the three designated areas on the grating surface in tandem. The measured first-order diffraction efficiencies at the respective centers of the areas are 1820%. The flat field spectrograph equipped with the grating indicates a spectral line width of 814 eV for the soft X-ray emission spectra generated from electron-impact X-ray sources.
Imazono, Takashi; Ishino, Masahiko; Koike, Masato; Sasai, Hiroyuki*; Sano, Kazuo*
Applied Optics, 46(28), p.7054 - 7060, 2007/10
Times Cited Count:18 Percentile:64.1(Optics)A multilayer laminar-type holographic grating having an average groove density of 2400 lines/mm is designed and fabricated for use with a soft X-ray flat field spectrograph covering the 0.70-0.75 nm region. A varied-line-spaced grooves pattern is generated by the use of an aspheric wavefront recording system and laminar-type grooves are formed by a reactive ion-etching method. Mo/SiO multilayers optimized for the emission lines of hafnium M, silicon K, and tungsten M are deposited on one of the three designated areas on the grating surface in tandem. The measured first-order diffraction efficiencies at the respective centers of the areas are 1820%. The flat field spectrograph equipped with the grating indicates a spectral line width of 814 eV for the emission spectra generated from electron-impact X-ray sources.
Ishino, Masahiko; Koike, Masato; Kanehira, Mika*; Sato, Futami*; Terauchi, Masami*; Sano, Kazuo*
Journal of Applied Physics, 102(2), p.023513_1 - 023513_5, 2007/07
Times Cited Count:6 Percentile:26.48(Physics, Applied)The heat stability of Co/SiO multilayers was evaluated. Multilayer samples were deposited on Si substrates by means of the ion beam sputtering method and annealed at temperatures from 100-600 C in a vacuum furnace. For the structural and optical evaluations, small angle X-ray diffraction measurements, soft X-ray reflectivity measurement in the 1 keV energy region, and transmission electron microscopy observations were carried out. As the results, the Co/SiO multilayers annealed up to 400 C maintained the initial multilayer structure and kept almost the same X-ray reflectivity as the as-deposited sample. A deterioration of the multilayer structure caused by the growth of Co grains was found on the samples annealed over 500 C, and the soft X-ray reflectivity dropped in accordance with the deterioration of the multilayer structure.
Koike, Masato; Ishino, Masahiko; Heimann, P. A.*; Imazono, Takashi; Takenaka, Hisataka*; Hatayama, Masatoshi*; Sasai, Hiroyuki*; Gullikson, E. M.*; Sano, Kazuo*
AIP Conference Proceedings 879, p.647 - 650, 2007/01
no abstracts in English
Ishino, Masahiko; Heimann, P. A.*; Sasai, Hiroyuki*; Hatayama, Masatoshi*; Takenaka, Hisataka*; Sano, Kazuo*; Gullikson, E. M.*; Koike, Masato
Applied Optics, 45(26), p.6741 - 6745, 2006/09
Times Cited Count:12 Percentile:50(Optics)no abstracts in English