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E Shigemasa

Publications and source records attributed to E Shigemasa.

14 recordsLinked to original sources

Nondipolar electron angular distributions from fixed-in-space molecules.

The first indication of nondipole effects in the azimuthal dependence of photoelectron angular distributions emitted from fixed-in-space molecules is demonstrated in N (2). Comparison of the results with angular distributions observed for randomly oriented molecules and theoretical derivations for the nondipole correction first order in photon momentum suggests that higher orders will be needed to describe distributions measured in the molecular frame.

Journal Article↗

Dynamical angular correlation in molecular Auger decay.

The first measurements of the angular distribution of Auger electrons from fixed-in-space molecules have been performed in the C K-shell ionization region of CO, for both parallel and perpendicular orientations of the molecular axis with respect to the light polarization vector. The angular distributions obtained for the CO(2+)B(1)Sigma Auger final state show dramatic spectral variations, which also depend on the initial ionization channels, Sigma or Pi, and on the ionization photon energy. This dynamical angular correlation process strongly suggests the breakdown of a two-step model in which the Auger decay is treated independently of the initial photoionization process.

Journal Article↗

Mg and Al K-edge XAFS measurements with a KTP crystal monochromator.

There has been a strong demand for monochromator crystals with a large lattice spacing in order to measure EXAFS spectra at the Mg and Al K-edges. We have introduced a pair of KTP crystal at BL1A of the UVSOR facility and examined its performance in the energy range between 1200 and 2000eV. This crystal monochromator can supply stable photon beams enough to measure the EXAFS spectra for the Mg and Al K-edges. Advantages of the KTP crystal are discussed in comparison with a YB66 crystal monochromator.

Journal Article↗