Michio Sasanuma

Soft X-Ray Absorption Spectra of Metals and Alloys. I. Be, Al, Sb, Bi and Al-Mg Alloys

Soft X-ray absorption spectra of Be, Al, Sb and Bi, and Al-Mg alloys have been obtained by the use of synchrotron radiation emitted from the 750 MeV electron synchrotron at the Institute for Nuclear Study, Tokyo, as a continuous light source. The K-absorption structure of beryllium was found to agree with the density of states calculated by Loucks and Cutler. Some correspondence was found between the maxima in the L 2,3 -absorption spectrum and the K-absorption spectrum of aluminum. A remarkable band was observed in the L 2,3 -absorption spectrum of aluminum at 23 eV above the edge. This band is not attributable to the singularity in the state density of the conduction band. A tentative interpretation based on the delayed onset of transitions 2 p -∞ d is proposed. The L 2,3 -absorption spectrum of aluminum in Al-Mg alloy shows a remarkable degeneration of the edge, while the L 2,3 -absorption edge of magnesium in the same alloy seems relatively unaffected. This behavior is similar to the effect reported b...

Absorption structures of SF6 in the VUV region

Absorption and ionisation efficiencies for SF6 have been measured in the VUV region. An analysis of the gross absorption structures is given by comparison of the experimental results in photoelectron spectroscopy with the absorption spectra of the sulphur L2,3. All the absorption structures in the VUV region observed are interpreted consistently with the two-well potential scheme. The vibrational progressions in the range 550-670 AA are also assigned to the Rydberg series caused by the transitions, 4t1u-nsa1g (n>or=3).

Cl− L23 absorption spectra of alkali chlorides obtained at 80°K with synchrotron radiation

Abstract Cl - L 23 absorption spectra of alkali chlorides have been obtained at 80°K with a 2 m grazing incidence spectrograph. Synchrotron radiation emitted from a 1.3 GeV electron synchrotron at INS ∗ has been used as a continuum background. The experimental results are interpreted in terms of X-ray exciton, electronic band structure, and two electron excitation.

K absorption structure of the nitrogen atom in the nitric oxide molecule

The absorption spectrum of the nitric oxide molecule in the 30 A region has been observed by using a 2 m grazing incidence spectrograph and synchrotron radiation from a 1.3 BeV electron synchroton as a background source. The spectrum has discrete structure and is similar to the spectrum, near the K edge, of the nitrogen molecule. The absorption structure is analyzed by drawing an analogy between the electron configuration of the states formed by the excitations of a (σ1s)N electron in nitric oxide to the outer orbitals and the electron configuration of the states formed by the excitations of the outermost orbital electron of oxygen molecule. The K absorption edge of the nitrogen atom in nitric oxide is determined to be 409.9±0.1 eV.

Photoionisation of SF6 in the XUV region

Photoionisation spectra of SF6 are obtained using synchrotron radiation and a quadrupole mass spectrometer in the region from 300 to 820 AA. Appearance potentials of SF5+, SF4+ and SF3+ are compared with other data by electron impact. Partial and total ionisation cross sections for the fragment ions in the photoionisation of SF6 are obtained by normalising the present total ionisation cross section to that obtained in the previous work at a certain wavelength.

On the Radiative Equilibrium Condition and the Thermal Radiation

Experimental examination of the reflection of light at the surface of noble metals at high temperature shows non existence of the radiative equilibrium condition and the induced emission. Interpretation of the thermal radiation is given without using the Plancks radiation formula and the Kirchhoffs law. Temperature shifts of the spectral peak of the emission band with increasing temperature are calculated by a quantum mechanical model, where the radiation is induced by an electron transition between two potentials and the spectral shape and shifts are determined by the Boltzmann factor in the potentials.

Silicon Wafer Half-Mirror in Far Infrared

Optical properties of silicon wafer are examined. Its low absorptance to IR light and stability in air, make it suitable for use as a half-mirror for light in the far IR.

Spectral Properties of Cavity Radiation: Nonuniversal Characteristics.

The spectral properties of thermal radiation from a stadium-type cavity are examined. The significant effects of the shape and material species of the cavity wall on the spectral intensity are observed. The fluctuation of radiation intensity amounts to ten percent of the standard intensity estimated by use of Plancks formula and reveals the non-equilibrium and non-universal nature of the cavity radiation.

An Analysis of the Reflective Structures of Amorphous Silica in IR

The reflective structures of the amorphous silica are examined from their temperature and angular dependent characteristics and also with a relation to the thermal radiation spectra. The reflective structures are analyzed as a photon scattering by a molecular unit localized at the top of the surface. Shift of the peak of the reflective structures with increasing temperature is interpreted as the temperature dependent perturbation from neighboring unit cells. An extrapolation of the frequency at the maximum reflectivity to 0 K gives the fundamental frequency of the vibrational mode.