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Sunao Takahashi

Bio: Sunao Takahashi is an academic researcher from Kobe Steel. The author has contributed to research in topics: Beamline & Undulator. The author has an hindex of 17, co-authored 50 publications receiving 2474 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the SPring-8 Angstrom Compact Free-Electron Laser (CFEL) was used for sub-angstrom fundamental-wavelength lasing at the Tokyo National Museum.
Abstract: Researchers report sub-angstrom fundamental-wavelength lasing at the SPring-8 Angstrom Compact Free-Electron Laser in Japan. The output has a maximum power of more than 10 GW, a pulse duration of 10−14 s and a lasing wavelength of 0.634 A.

1,467 citations

Journal ArticleDOI
TL;DR: In this paper, a 55m-long compact self-amplified spontaneous emission (SEM) source with a low acceleration energy of 250 MeV was used to generate X-ray free-electron laser radiation with a 2-GeV machine.
Abstract: Single-pass free-electron lasers based on self-amplified spontaneous emission1,2,3,4 are enabling the generation of laser light at ever shorter wavelengths, including extreme ultraviolet5, soft X-rays and even hard X-rays6,7,8. A typical X-ray free-electron laser is a few kilometres in length and requires an electron-beam energy higher than 10 GeV (refs 6, 8). If such light sources are to become accessible to more researchers, a significant reduction in scale is desirable Here, we report observations of brilliant extreme-ultraviolet radiation from a 55-m-long compact self-amplified spontaneous-emission source, which combines short-period undulators with a high-quality electron source operating at a low acceleration energy of 250 MeV. The radiation power reaches saturation at wavelengths ranging from 51 to 61 nm with a maximum pulse energy of 30 µJ. The ultralow emittance (0.6π mm mrad) of the electron beam from a CeB6 thermionic cathode9 is barely degraded by a multiple-stage bunch compression system that dramatically enhances the beam current from 1 to 300 A. This achievement expands the potential for generating X-ray free-electron laser radiation with a compact 2-GeV machine. Free-electron lasers can produce powerful pulses of radiation at very short wavelengths, even in the hard-X-ray region. In general, however, they comprise facilities several kilometres in length. A 55-m-long laser could open up the technology to a broader range of researchers.

369 citations

Journal ArticleDOI
TL;DR: The frontier soft-material beamline at BL03XU for soft materials was recently installed at SPring-8, using an in-vacuum undulator.
Abstract: A new beamline called the frontier soft-material beamline at BL03XU for soft materials was recently installed at SPring-8, using an in-vacuum undulator. The photon flux can reach 1013 photons sec−1 and the energy resolution is about 10−4 at an energy of 12.4 keV. The present paper introduces details on the instrumental and some of the first scattering data measured at BL03XU, revealing its cutting-edge design and high performance.

105 citations

Journal ArticleDOI
TL;DR: The design and performance of a new soft X-ray beamline BL07LSU at SPring-8 is described, which has achieved high energy resolution and high photon flux in the photon energy range 250–2000 eV with fully controllable polarization.
Abstract: A new soft X-ray beamline, BL07LSU, has been constructed at SPring-8 to perform advanced soft X-ray spectroscopy for materials science. The beamline is designed to achieve high energy resolution (E/ΔE> 10000) and high photon flux [>1012 photons s−1 (0.01% bandwidth)−1] in the photon energy range 250–2000 eV with controllable polarization. To realise this state-of-the-art performance, a novel segmented cross undulator was developed and adopted as a light source. The details of the undulator light source and beamline monochromator design are described. The achieved performance of the beamline, such as the photon flux, energy resolution and the state of polarization, is reported.

93 citations

Journal ArticleDOI
TL;DR: The commissioning studies and an application to a uranium compound with the helicity-switching mode of a new twin-helical undulator installed in soft X-ray beamline BL23SU at SPring-8 are described.
Abstract: The soft X-ray beamline BL23SU at SPring-8 has undergone an upgrade with a twin-helical undulator of in-vacuum type to enhance the experimental capabilities of the endstations. The new light source with a fast helicity-switching operation allows not only the data throughput but also the sensitivity in X-ray magnetic circular dichroism (XMCD) to be improved. The operational performance and potential are described by presenting XMCD results of paramagnetic β-US2 measured with a 10 T superconducting magnet.

92 citations


Cited by
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Journal ArticleDOI
TL;DR: The Linac Coherent Light Source free-electron laser has achieved coherent X-ray generation down to a wavelength of 1.2 A and at a brightness that is nearly ten orders of magnitude higher than conventional synchrotrons.
Abstract: The Linac Coherent Light Source free-electron laser has now achieved coherent X-ray generation down to a wavelength of 1.2 A and at a brightness that is nearly ten orders of magnitude higher than conventional synchrotrons. Researchers detail the first operation and beam characteristics of the system, which give hope for imaging at atomic spatial and temporal scales.

2,648 citations

01 Jan 2016
TL;DR: In this paper, the authors present the principles of optics electromagnetic theory of propagation interference and diffraction of light, which can be used to find a good book with a cup of coffee in the afternoon, instead of facing with some infectious bugs inside their computer.
Abstract: Thank you for reading principles of optics electromagnetic theory of propagation interference and diffraction of light. As you may know, people have search hundreds times for their favorite novels like this principles of optics electromagnetic theory of propagation interference and diffraction of light, but end up in harmful downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious bugs inside their computer.

2,213 citations

Journal ArticleDOI
TL;DR: It is shown that the penetration and efficacy of the larger micelles could be enhanced by using a transforming growth factor-β inhibitor to increase the permeability of the tumours.
Abstract: Drug-loaded polymeric micelles with a diameter of 30 nm can penetrate poorly permeable tumours to achieve an antitumour effect.

2,026 citations

Journal ArticleDOI
TL;DR: In this paper, the SPring-8 Angstrom Compact Free-Electron Laser (CFEL) was used for sub-angstrom fundamental-wavelength lasing at the Tokyo National Museum.
Abstract: Researchers report sub-angstrom fundamental-wavelength lasing at the SPring-8 Angstrom Compact Free-Electron Laser in Japan. The output has a maximum power of more than 10 GW, a pulse duration of 10−14 s and a lasing wavelength of 0.634 A.

1,467 citations

01 Sep 1994
TL;DR: In this article, the authors present a review of Charged Particle Dynamics and Focusing Systems without Space Charge, including Linear Beam Optics with Space Charge and Self-Consistent Theory of Beams.
Abstract: Review of Charged Particle Dynamics. Beam Optics and Focusing Systems Without Space Charge. Linear Beam Optics with Space Charge. Self-Consistent Theory of Beams. Emittance Variation. Beam Physics Research from 1993 to 2007. Appendices. List of Frequently Used Symbols. Bibliography. Index.

1,311 citations