Eiji Shigemasa

Bio: Eiji Shigemasa is an academic researcher from National Institutes of Natural Sciences, Japan. The author has contributed to research in topics: Ionization & Excited state. The author has an hindex of 23, co-authored 63 publications receiving 1783 citations. Previous affiliations of Eiji Shigemasa include Okayama University & Graduate University for Advanced Studies.

Angular Distributions of 1 s σ Photoelectrons from Fixed-in-Space N 2 Molecules

Abstract: The angular distributions of $1s\ensuremath{\sigma}$ photoelectrons from ${\mathrm{N}}_{2}$ molecules held fixed in space have been measured around the ${\ensuremath{\sigma}}^{*}$ shape resonance for the first time. The angular distributions have been very rich in structure, which are completely different from usual photoelectron angular distributions from randomly oriented molecules, as predicted by Dill. The orbital angular momentum properties of the $1s\ensuremath{\sigma}$ photoelectrons around the ${\ensuremath{\sigma}}^{*}$ shape resonance have been made clear from the angular distribution patterns.

X-ray two-photon absorption competing against single and sequential multiphoton processes

Abstract: The first observation of a third-order process induced by an X-ray beam from a free-electron laser is realized in germanium using a 5.6-keV X-ray beam. Two-photon absorption is confirmed, suggesting that X-ray analogues of other third-order nonlinear processes may be available for exploitation in X-ray experiments.

Properties of hollow molecules probed by single-photon double ionization.

Abstract: The formation of hollow molecules (with a completely empty K shell in one constituent atom) through single-photon core double ionization has been demonstrated using a sensitive magnetic bottle experimental technique combined with synchrotron radiation. Detailed properties are presented such as the spectroscopy, formation, and decay dynamics of the N(2)(2+) K(-2) main and satellite states and the strong chemical shifts of double K holes on an oxygen atom in CO, CO2, and O2 molecules.

Recoil-ion and electron momentum spectroscopy: reaction-microscopes

Abstract: Recoil-ion and electron momentum spectroscopy is a rapidly developing technique that allows one to measure the vector momenta of several ions and electrons resulting from atomic or molecular fragmentation. In a unique combination, large solid angles close to 4π and superior momentum resolutions around a few per cent of an atomic unit (a.u.) are typically reached in state-of-the art machines, so-called reaction-microscopes. Evolving from recoil-ion and cold target recoil-ion momentum spectroscopy (COLTRIMS), reaction-microscopes—the `bubble chambers of atomic physics'—mark the decisive step forward to investigate many-particle quantum-dynamics occurring when atomic and molecular systems or even surfaces and solids are exposed to time-dependent external electromagnetic fields. This paper concentrates on just these latest technical developments and on at least four new classes of fragmentation experiments that have emerged within about the last five years. First, multi-dimensional images in momentum space brought unprecedented information on the dynamics of single-photon induced fragmentation of fixed-in-space molecules and on their structure. Second, a break-through in the investigation of high-intensity short-pulse laser induced fragmentation of atoms and molecules has been achieved by using reaction-microscopes. Third, for electron and ion-impact, the investigation of two-electron reactions has matured to a state such that the first fully differential cross sections (FDCSs) are reported. Fourth, comprehensive sets of FDCSs for single ionization of atoms by ion-impact, the most basic atomic fragmentation reaction, brought new insight, a couple of surprises and unexpected challenges to theory at keV to GeV collision energies. In addition, a brief summary on the kinematics is provided at the beginning. Finally, the rich future potential of the method is briefly envisaged.

X-Rays and Extreme Ultraviolet Radiation: Principles and Applications

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.