Kunitsugu Soda

Rotatory‐Diffusion Broadening of Rayleigh Lines Scattered from Optically Anisotropic Macromolecules in Solution

A technique for the spectroscopic detection of pure rotatory Brownian movement of anisotropic macromolecules in solution are developed in combination with a high‐resolution optical heterodyne spectrometer. The line broadening originating in the translational diffusion of the solute macromolecule, which is a dominant factor in intensity in the Rayleigh component, is suppressed by taking the forward scattering. Then, only the depolarized light whose amplitude is fully modulated by the rotation of solute molecules is filtered off by the polarizer and received by a photomultiplier tube. The time‐dependent component of the output from the phototube is analyzed by a wave analyzer to give a spectrum of the scattered light. From the spectral linewidth thus obtained, the rotatory diffusion coefficient of Tobacco Mosaic Virus in aqueous solution has been obtained and found to be 350 ± 20 sec−1. On the other hand, the optically isotropic polystyrene latex sphere has shown no broadening in this system. From these res...

Depolarized Light Mixing for Light Beating Spectroscopy

The depolarized light mixing (DLM) system is presented as a useful device in light beating spectroscopy for the observation of molecular rotation, deformation, and reaction which accompany an anisotropic change of polarizability. The system has the following merits: (1) Doppler broadening does not appear because it observes forward scattering; (2) only the line shape coming from a pure anisotropic polarizability change is obtained; (3) it can work automatically as an optical heterodyne system with the stray light from the second polarizer serving as a local oscillator light; (4) there is no difficulty in matching the wavefronts of the scattered light and local oscillator beam; and (5) the scattering volume can be made large without diminishing the efficiency of light beating. These characteristics are described through the numerical evaluation of beating efficiency and signal‐to‐noise ratio.

Electronic structures of U3P4 and U3As4 studied by synchrotron radiation photoemission spectroscopy

Abstract Photoemission spectra and their resonant behavior at the 5d core threshold were measured with synchrotron radiation. 5f derived features were observed close to the Fermi level as well as at 2.0(1.89) eV for U 3 P 4 (U 3 As 4 ). An additional peak was observed around 5.5 eV for U 3 As 4 . This structure seems to correspond to the p-f bonding states in Ce monopnictides.

Analysis of noises in photocurrent time‐correlation spectroscopy of scattered light

A covariance function, VN (τ,σ), is introduced for the analysis of noises in photocurrent time‐correlation spectroscopy of scattered light. Its explicit forms under various measuring conditions are given and the characteristics and magnitudes of the noises are investigated. The distortion of a correlation function caused by the truncation of both upper and lower frequency ranges is examined. The reason for the absence of the so‐called aliasing error in a Gaussian‐photocurrent correlation measurement is given.

A UPS study of liquid and solid bismuth using synchrotron radiation

The photoelectron spectra of Bi in both liquid and solid phases were measured at excitation energies between 18 and 60 eV using synchrotron radiation. It was found that the profiles of the energy distribution curves are quite similar to those obtained in the XPS region and there is little difference in the spectral profile between liquid and solid phases. On melting the density of states at the Fermi level increases more than twice as much as in the solid phase. In both liquid and solid phases, the photoelectron spectra change their profiles associated with the 5d core electron excitation, which is attributed to the O4.5VV Auger electrons.

VUV studies on the 4f partial states in lanthanide-copper compounds

Energy distributions of the 4f partial states in lanthanide-copper compounds, RCu6 (R = Ce, Pr, Nd and Sm) and CexLa1-xCu6 (x = 0, 0.2, 0.5, 0.8 and 1.0), have been measured by means of 4d-4f resonant photoemission. Main 4f peaks shift toward the high binding energy and the 4f partial density of states near the Fermi edge decreases successively in the order of CeCu6, PrCu6 and NdCu6. In SmCu6, an appreciable magnitude of the 4f feature is observed near the Fermi edge in addition to the main feature occurring above 4 eV indicating the coexistence of Sm2+ and Sm3+ ions in this compound. The main 4f feature in CexLa1-xCu6 can be approximated by a Lorentzian shape. The location of the 4f peak and its width are dependent on the concentration of 4f electrons. The shape of the 3D1 line of the lanthanum ion as observed in partial yield spectra varies with the concentration of lanthanum ions.

Resonant photoemission study of CeCu2 and CeCu6

Abstract Resonant photoemission has been observed for CeCu 2 and CeCu 6 to investigate the Ce 4f states of these materials. In contrast to the case of other heavy fermion systems, it is found that the Ce 4f spectra of these compounds have no definite double-peak structure.

A new VUV beamline BL‐19 for undulator radiation at the Photon Factory

A new VUV beamline at the Photon Factory ring that is designed to accept radiation emitted from an undulator is described. The characteristics of the undulator and all parts of the beamline; a front end, a mirror system, and two monochromators, are described in detail. The characteristics of optical elements in the beamline are also shown.

Rapid investigation of sedimentation phenomena by vibrational force field

A new method for the rapid investigation of sedimentation phenomena of fine particles is developed by using the force due to a vibrational acceleration. The small displacement of the particle with respect to the wall of the container, which is produced by the vibration, is measured by the interference between the light scattered by the particle and that of the cell wall. The interference is detected as a beat note in the scattered-light intensity, and displayed as a time-autocorrelation of the photocurrent, the analysis of which gives the sedimentation coefficient and the dispersion.

Photoemission Spectra of CeCu2Si2 and CeInCu2

Photoelectron energy distribution curves have been measured on CeCu2Si2 and CeInCu2. In CeCu2Si2, the spectra for low-energy excitations reflect energy band density-of-states curves qualitatively well. The 4f partial energy distribution curve obtained by using the 4d-4f resonance shows no prominent peak but a broad band with weak features extending over an energy range within 4 eV from the Fermi edge. This is quite contrasted to the aspect observed in other cerium compounds. The observed energy distribution of the 4f partial states does not reflect the calculated distribution of the 4f component of the energy band. In CeInCu2, the 4f partial energy distribution curve has a two-peak structure.