Kohjiro Kobayashi

Radial integrals for the magnetic form factor of 5d transition elements.

The radial integrals, j(L), where L = 0, 2, 4, for several electronic configurations in the 5d electrons of transition metal atoms and ions are calculated using radial wavefunctions from the pseudo-relativistic Hartree-Fock method in the Cowan program. The resultant values are fitted to Gaussian analytical expressions with four exponential terms, and the fitted coefficients are tabulated. This table can be used to interpret the magnetic form factor measurements for 5d transition metals.

Multi-point differential laser doppler velocimeter using arrayed waveguide gratings with small wavelength sensitivity

A multi-point laser Doppler velocimeter (LDV) using the arrayed waveguide gratings (AWGs) with small wavelength sensitivity (less than 1/10 of that for a conventional LDV without the AWGs) is proposed, in which velocities at different points in the depth direction can be simultaneously measured with compact optical systems. The design and characteristics of the proposed LDV are investigated with the model using the grating equation of the AWGs. From our simulation results, the wavelength sensitivity for multiple measured points can be reduced to less than 1/10 of that for a conventional LDV without an AWG.

Accurate Compton scattering measurements for N2 molecules

The accurate Compton profiles of N2 gas were measured using 121.7 keV synchrotron x-rays. The present accurate measurement proves the better agreement of the CI (configuration interaction) calculation than the Hartree?Fock calculation and suggests the importance of multi-excitation in the CI calculations for the accuracy of wavefunctions in ground states.

Analysis of autocorrelation functions calculated from Compton profiles of a N2 molecule using the DV-Xα method

Compton profiles and autocorrelation functions for a N2 molecule are calculated using the discrete variational Xα (DV-Xα) method and compared with recent and accurate measurements of the Compton profile of N2 gas and Compton profiles calculated using the Hartree–Fock and the configuration interaction methods. The autocorrelation function shows a position dependence on the electron correlation. The molecular orbital dependence of the autocorrelation function reveals that the π molecular orbitals are the most sensitive to α values in the DV-Xα method.

Radial integrals for the magnetic form factor of the 5d electrons of rare earth elements.

The radial integrals , where L = 0, 2, 4, for several electronic configurations of the 5d electrons of rare earth elements are calculated using radial wavefunctions from the Hartree-Fock relativistic method in the Cowan program. Gaussian analytical expressions with four exponential terms are fitted to the values for rare earth elements and the fitted coefficients are tabulated. The tables can be used to interpret the form factor measurements for rare earth metals. Using the radial integrals of Ce 4f and 5d electrons, the experimental measurement of the magnetic form factor of CePd(3) is investigated.

Calculation of Compton Profiles Using the DV-Xα Method for 14 Electron Diatomic Molecules

Isotropic and directional Compton profiles are calculated for 14 electron diatomic molecules, N2, CO, and BF, using the DV-Xα method. In order to investigate the effect of chemical bonding for Compton profiles, parallel and perpendicular directional Compton profiles to the molecules are calculated and compared with the results from Hartree-Fock and configuration interaction methods. The DV-Xα method could describe the more detailed character of covalent bonding than that of ionic bonding.

Calculation of Compton Profiles for Rare Gases Using the DV-Xα Method

Compton profiles related to the electron momentum distribution are calculated using the DV-Xα method for a series of rare gases from He to Rn. To verify the criteria of the DV-Xα-derived Compton profiles, our results are compared with those obtained from the Hartree-Fock method. The trend of Compton profiles obtained from the DV-Xα method is discussed.

Microforce Material Tester Using Small Pendulum

A method of inexpensive material tester is proposed for realizing an instrument based on the levitation mass method without the use of pneumatic linear bearings and a Zeeman type two frequency He-Ne laser. As an example a material tester using the pendulum, which evaluates the mechanical response of general objects against impact forces, is developed. The characteristics of the restoring force are determined using the same instrument under the free-swing condition without the object under test. To demonstrate the performance of the developed instrument, the impact response of a gel block is determined.