Direct actinide assay with surface passivated silicon diodes

Summary The determination of transuranic (TRU) content in nuclear wastes, reactor materials, process solutions, and various other matrices is required in support of material assessment, environmental restoration, and waste processing activities. We have found that direct measurement of TRU is possible using surface passivated ion implanted planar silicon diode detectors. The performance and durability of modern silicon diodes enables direct detection of alpha-particles, with retention of some spectral information, through small air gaps or under direct contact with liquid or solid samples. We will present results on the performance of silicon diode detectors for the determination of TRU in liquids.     

The vibrational spectrum of thionynyl fluoride and its oxygen-18 isotopomer[1]

The vibrational spectrum of thionyl fluoride, SOF₂, has been reinvestigated by means of high resolution infrared and Raman spectroscopy. Substitution of oxygen-16 by oxygen-18 led to a definitive identification of those modes to which sulfur-oxygen motion makes a large contribution. The band structure of the sulfur-oxygen stretching vibration, which is obscured by Fermi resonance with a combination band in S¹⁶OF₂, has been resolved in S¹⁸OF₂. The experimental isotopic splittings are compared with those calculated by previous investigators.     

Application of modified normal pulse polarography and its differential mode to alkaline-earth metal ions in acid solutions

The simultaneous determination of alkaline-earth metal ions in acid solution was studied by modified normal pulse polarography. Well-defined waves were recorded for calcium, strontium and barium, but no limiting current was found for magnesium, because of its very negative reduction potential. The differential mode of this method gives peak-type polarograms and is useful for the simultaneous determination of species for which the half-wave potentials lie close together. The interference of dissolved oxygen was eliminated by the use of tetramethylammonium chloride as a supporting electrolyte.     

Detection of multivariate outliers with location slippage or scale inflation in left orthogonally invariant or elliptically contoured distributions

This paper is concerned with two kinds of multiple outlier problems in multivariate regression. One is a multiple location-slippage problem and the other is a multiple scale-inflation problem. A multi-decision rule is proposed. Its optimality is shown for the first problem in a class of left orthogonally invariant distributions and is also shown for the second problem in a class of elliptically contoured distributions. Thus the decision rule is robust against departures from normality. Further the null robustness of the decision statistic which the rule is based on is pointed out in each problem.     

Scattering of ion beam by the current-driven ion wave turbulence

The effective scattering of an ion beam by the ion wave turbulence is investigated experimentally. The results are compared with the values predicted theoretically.     

A derivation of the compressibility equation for liquid metals

The Kirkwood and Buff compressibility equation for multicomponent systems is applied to an assembly of ions and electrons, where the Coulomb potential is replaced by the Yukawa potential. It is then shown that the resulting formula gives the Watabe-Hasegawa-Chihara compressibility equation in the limit of infinitesimal damping constant of the Yukawa potential.     

Proton decay

The lifetimes and branching ratios of the proton and bound neutron are calculated in the SO(10) grand unified theory by taking into account the form factor effect (by making use of SU(6) symmetric wave functions for the nucleons and mesons) and the generation mixing, based on the assumption that the ΔB = ? 1 decay interaction is generated by the exchange of superheavy leptoquark gauge bosons, D (X and Y) and E (X' and Y'). In our approach there is a free parameter M_D/M_E, which should be determined by experiment. The branching ratio of the inclusive decay of an I = 0 nucleus into neutrinos and anything is found to be most dependent on the ratio M_D/M_E. The nucleon lifetime is τ_N = [M_D (GeV)/5 × 10¹⁴]⁴ × (0.0015,2.5,4.6) × (1_?0.4⁺²) × 10³⁰ year, for M_D/M_E = (10,1,0.1). Only the cases in which M_DapM_E are found to be possible for Λ_ms[? 0.26 GeV and τ_N ? 5 × 10³⁰ year if there is not a fourth generation of light fermions, technicolored particles nor supersymmetric particles.