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Kouji Inagaki

Bio: Kouji Inagaki is an academic researcher from Osaka University. The author has contributed to research in topics: Etching (microfabrication) & HOMO/LUMO. The author has an hindex of 12, co-authored 49 publications receiving 1078 citations.


Papers
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Journal ArticleDOI
TL;DR: In this paper, an in situ technique that corrects for wavefront aberrations and allows X-rays to be focused to a spot just 7 nm wide could provide a solution.
Abstract: X-ray sources such as free-electron lasers offer the potential to study matter at unprecedented spatial and temporal resolution. But that potential is limited by the poor quality of conventional X-ray optical elements. An in situ technique that corrects for wavefront aberrations and allows X-rays to be focused to a spot just 7 nm wide could provide a solution.

493 citations

Journal ArticleDOI
TL;DR: In this article, a numerically controlled elastic emission machining (EEM) system was developed to fabricate ultraprecise optical components, particularly in x-ray optics, by which a high shear-rate flow of ultrapure water can be generated on the work surface, to transport the fine powder particles to the processing surface.
Abstract: A numerically controlled elastic emission machining (EEM) system has been developed to fabricate ultraprecise optical components, particularly in x-ray optics. Nozzle-type EEM heads, by which a high shear-rate flow of ultrapure water can be generated on the work surface, have been newly proposed to transport the fine powder particles to the processing surface. Using this type of EEM head, the obtainable spatial resolution in figure correction can be changed by selecting the suitable aperture size of the nozzle according to the required spatial frequency. As a result of test figuring, 1 nm level peak-to-valley (p–v) accuracy is achieved throughout the entire spatial wavelength range longer than 0.3 mm. In addition, the microroughness of the processed surface is certified to also be approximately 1 nm (p–v).

234 citations

Journal ArticleDOI
TL;DR: It is concluded that CO2 does not dissociate on "ideal" flat, stepped, or kinked Cu surfaces at low temperature to other factors such as effects of Cu adatoms, gas phase or condensed CO2 molecules, or interaction with other gas phase molecules.
Abstract: We studied the dissociative adsorption of CO2 to CO + O on the Cu(111), Cu(221), Cu(211), and Cu(11 5 9) surfaces by using state-of-the-art density functional theory (DFT) within a generalized gradient approximation (GGA) and van der Waals density functional (vdW-DF) calculations. The activation energy for CO2 dissociation on the flat Cu(111) surface is 1.33 eV. The activation energies on stepped and kinked surfaces are 1.06 eV, 0.67 eV, and 1.02 eV for the Cu(221), Cu(211), and Cu(11 5 9) surfaces, respectively. Even though the activation energy is 0.66 eV lower on the stepped Cu(211) surface than on the flat Cu(111) surface, we conclude that CO2 does not dissociate on “ideal” flat, stepped, or kinked Cu surfaces at low temperature. We attribute the discrepancy between our theoretical results and experimentally observed CO2 dissociation on stepped Cu surfaces below 150 K to other factors such as effects of Cu adatoms, gas phase or condensed CO2 molecules, or interaction with other gas phase molecules.

61 citations

Journal ArticleDOI
TL;DR: By tuning the dipole-dipole interaction based on the electronic natures of the HOMO and the LUMO, this work describes a slipped-stacked ZnPc dimer configuration in which the Q-band absorption wavelength increases by as large as 144 nm relative to the monomer Q- band.
Abstract: We investigate electronic origins of a redshift in absorption spectra of a dimerized zinc phthalocyanine molecule (ZnPc) by means of hybrid density functional theoretical calculations. In terms of the molecular orbital (MO) picture, the dimerization splits energy levels of frontier MOs such as the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the constituent molecules. Consequently, the absorption wavelength seems to become longer than the monomer as the overlap between the monomers becomes larger. However, for a ZnPc dimer configuration with its cofacially stacked monomer arrangement, the calculated absorption spectra within the time-dependent density functional theory indicates no redshift but blueshift in the Q-band absorption spectrum, i.e., a typical H-aggregate. The origin of the apparently contradictory result is elucidated by the conventional description of the interaction between monomer transition dipoles in molecular dimers [Kasha, M. Radiat. Res. 1963, 20, 55]. The redshift is caused by an interaction between the two head-to-tail transition dipoles of the monomers, while the side-by-side arranged transition dipoles result in a blueshift. By tuning the dipole-dipole interaction based on the electronic natures of the HOMO and the LUMO, we describe a slipped-stacked ZnPc dimer configuration in which the Q-band absorption wavelength increases by as large as 144 nm relative to the monomer Q-band.

38 citations

Journal ArticleDOI
TL;DR: In this article, a bendable adaptive optical system that can be used in the hard X-ray region was developed to achieve highly precise control of the wavefront shape, and demonstrated the controllability of a wavefront of a 15 nm hard Xray nanobeam.
Abstract: A highly precise adaptive optical system that can be used in the hard X-ray region was developed. To achieve highly precise control of the wavefront shape, we discussed an optical system with a bendable mirror of deformation accuracy better than 0.4 nm RMS. Using the system, we demonstrated the controllability of the wavefront of a 15 nm hard X-ray nanobeam. The intensity profile of the wavefront-modified beam was in good agreement with the wave-optically calculated profile.

27 citations


Cited by
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TL;DR: In this article, a review of recent investigations on high-energy processes within the realm of relativistic quantum dynamics, quantum electrodynamics, and nuclear and particle physics, occurring in extremely intense laser fields is presented.
Abstract: The field of laser-matter interaction traditionally deals with the response of atoms, molecules, and plasmas to an external light wave. However, the recent sustained technological progress is opening up the possibility of employing intense laser radiation to trigger or substantially influence physical processes beyond atomic-physics energy scales. Available optical laser intensities exceeding ${10}^{22}\text{ }\text{ }\mathrm{W}/{\mathrm{cm}}^{2}$ can push the fundamental light-electron interaction to the extreme limit where radiation-reaction effects dominate the electron dynamics, can shed light on the structure of the quantum vacuum, and can trigger the creation of particles such as electrons, muons, and pions and their corresponding antiparticles. Also, novel sources of intense coherent high-energy photons and laser-based particle colliders can pave the way to nuclear quantum optics and may even allow for the potential discovery of new particles beyond the standard model. These are the main topics of this article, which is devoted to a review of recent investigations on high-energy processes within the realm of relativistic quantum dynamics, quantum electrodynamics, and nuclear and particle physics, occurring in extremely intense laser fields.

1,394 citations

Book
30 Apr 2020
TL;DR: In this paper, the fundamental properties of soft x-rays and extreme ultraviolet (EUV) radiation are discussed and their applications in a wide variety of fields, including EUV lithography for semiconductor chip manufacture and soft X-ray biomicroscopy.
Abstract: This self-contained, comprehensive book describes the fundamental properties of soft x-rays and extreme ultraviolet (EUV) radiation and discusses their applications in a wide variety of fields, including EUV lithography for semiconductor chip manufacture and soft x-ray biomicroscopy. The author begins by presenting the relevant basic principles such as radiation and scattering, wave propagation, diffraction, and coherence. He then goes on to examine a broad range of phenomena and applications. The topics covered include EUV lithography, biomicroscopy, spectromicroscopy, EUV astronomy, synchrotron radiation, and soft x-ray lasers. He also provides a great deal of useful reference material such as electron binding energies, characteristic emission lines and photo-absorption cross-sections. The book will be of great interest to graduate students and researchers in engineering, physics, chemistry, and the life sciences. It will also appeal to practicing engineers involved in semiconductor fabrication and materials science.

786 citations

Journal ArticleDOI
TL;DR: A review of recent work in the development of direct image-forming X-ray microscopy techniques and the relevant applications can be found in this article, including three-dimensional biological tomography, dynamical processes in magnetic nanostructures, chemical speciation studies, industrial applications related to solar cells and batteries, and studies of archaeological materials.
Abstract: Recent years have seen significant progress in the field of soft- and hard-X-ray microscopy, both technically, through developments in source, optics and imaging methodologies, and also scientifically, through a wide range of applications While an ever-growing community is pursuing the extensive applications of today's available X-ray tools, other groups are investigating improvements in techniques, including new optics, higher spatial resolutions, brighter compact sources and shorter-duration X-ray pulses This Review covers recent work in the development of direct image-forming X-ray microscopy techniques and the relevant applications, including three-dimensional biological tomography, dynamical processes in magnetic nanostructures, chemical speciation studies, industrial applications related to solar cells and batteries, and studies of archaeological materials and historical works of art

567 citations