Temporal interference effects by a pair of two-frequency laser beams — application to extremely low velocity measurements

A new proposal is described for the detection of low Doppler-frequency shifts or small displacements. The temporal interference term is expressed in terms of a beat-frequency wave with no phase term. Its amplitude is the same as the intensity formula produced by two equal-frequency laser beams. The significant low Doppler-frequency shifts included in this intensity formula, usually imbeded in the unwanted low frequency noise-spectra, becomes detectable from the amplitude of the beat-frequency wave. An application to a cross-beam Doppler velocimetry is successful for measurements down to the Doppler shifts as low as 0.03 Hz, corresponding to the velocity of 0.1 μm/s.     

Inclusive strange particle production in π−p interactions at 6 GeV/c

The inclusive production of Λ, K_S⁰, Σ^±(1385) and $\text{K}{}^{\mathrm{1\pm }}\text{(892)}$ in π^?p interactions at 6 GeV/c has been studied. The observed cross sections are: σ(Λ)=0.94±0.06 mb, σ(K_S⁰)=0.98±0.06 mb, σ(Σ⁺(1385))=60±7 μb, σ(Σ^?(1385))=90±9 μb, $\text{σ(}\text{K}{}^{\mathrm{1+}}\text{(892))=216±28 μ}\text{b and}\text{σ(}\text{K}{}^{\mathrm{1?}}\text{(892))=41±8 μ}\text{b}$, respectively. The inclusive spectra of these particles are presented as functions of squared transverse momentum and Feynman scaling variable x. The polarization of Λ has also been investigated. It is found from a comparison with higher-energy data that the inclusive cross sections for Σ^±(1385) and the production ratios Σ^±(1385)/Λ in π^?p at 6 GeV/c have not reached the high-energy limiting values.     

Anomaly of specific heat due to kinks

Finite temperature corrections to classical kink free energies for the sine-Gordon and ø⁴ chains are obtained analytically by means of the transfer integral method. These corrections reveal that kink excitations cause a Schottky-type anomaly of specific heat at low temperatures. The numerical results of Schneider and Stoll are explained qualitatively.     

Calculations of photoelectron spectra for tetrahedral oxyanions by the Hartree—Fock—Slater model

The electronic structures of typical oxyanions are studied using the discrete variational (DV)—Xα cluster method. The level structures calculated for the clusters correspond very well with the valence-state levels found in experimental XPS spectra. Theoretical intensities of the XPS peaks are evaluated, using the orbital populations obtained with the DV—Xα method together with atomic subshell photoionization cross-sections obtained in previous work with the same electron model. The results are in good agreement with experiment.     

Determination of niobium, titanium and zirconium by high-frequency plasma torch emission spectrometry and its application to steel

The basic conditions for the determination of niobium, titanium and zirconium with an argon plasma and a Hitachi UHF Plasma Spectrascan operated at 2450 MHz and 450 W maximum output, have been established. The niobium 405.89-nm, titanium 365.35-nm and zirconium 339.19-nm lines gave detection limits of 0.5, 0.1 and 2.0 p.p.m., respectively, when pure solutions were used. Effects of gas flow rates, high-frequency output and concentration of acids were examined. In applications to steel, titanium was determined without prior chemical separation from iron at the 499.95-nm line, whereas niobium and zirconium could not be determined in the presence of large amounts of iron. When a cupferron precipitation method followed by extraction of iron with methyl isobutyl ketone was applied, satisfactory results were obtained.