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  • Author or Editor: Y. Shiokawa x
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Abstract

We investigate linear relations between pattern sequences in a 〈q,r〉-numeration system, and give a basis of the module generated by pattern sequences for words of length not exceeding l. The expressions of pattern sequences using the basis are also studied. Similar results are obtained for the module generated by all pattern sequences.

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Abstract  

Alpha-ray spectrometry is at present a powerful analytical tool for the identification and assay of the transuranium elements. However, the energy resolution is not necessarily excellent and a tailing toward the lower energy side in the spectrum is observed. Then, the possibility utilizing internal conversion electron spectrometry as the improved analytical tool was examined. In this paper the construction of an internal conversion electron spectrometer with excellent energy resolution using a silicon surface barrier detector and its application to analysis of a mixture of243Cm/244Cm is described.

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Abstract  

Preparation of thin films of lanthanide (Ln) sulfides has been studied by the chemical vapor deposition (CVD) method, using metal -diketonato chelates with 2,2,6,6-tetramethyl-3,5-heptanedione and reactant H2S gas as starting materials. Two kinds of sulfides, Ln2O2S oxysulfides and EuS monosulfide, were obtained as thin films at temperatures as low as 390–570 °C. The CVD method was confirmed to be suited for the above purpose.

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Abstract  

Isotopic analysis of243Cm and244Cm has been tried by using a newly developed internal conversion electron spectrometer with high energy resolution. As a result, it was demonstrated that the above isotopes can be determined individually, accurately and precisely, and that the isotopic ratio is also possible to determined sensitively by measuring only the ratio of gross counting rate of internal conversion electrons to that of alpha-rays.

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Abstract  

The interaction of Ra2+, Sr2+ and Ba2+ with 1,4,7,10,13,16-hexaoxacyclooctadenace /18-crown-6/ in an aqueous solution was investigated by radio- and dc polarography. It was found that all these ions form 11 complexes with 18-crown-6 and their stability constants, lg K, are 3.43 for Ra2+, 2.40 for Sr2+ and 3.67 for Ba2+, respectively. The stability constant for Am2+ was estimated from the relationship between lg K for Sr2+, Ba2+, Ra2+, Eu2+, Yb2+ and Cf2+ and the ionic radii.

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Abstract  

Preparation of lanthanide fluoride and chloride films has been studied by chemical vapor deposition (CVD) using Ln(thd)3 (Ln=lanthanide(III); thd=2,2,6,6-tetramethyl-3,5-heptanedionato ligand) and Y(thd)3 with gas mixture systems of CF2Cl2 (difluorodichloromethane)/O2 and CF2Cl2/H2. Two kinds of fluorides, LnOF oxyfluoride and LnF3 triffluoride, were obtained separately along a CVD tube at atmospheric pressure and temperature as low as 300–600°C by the reaction of Ln(thd)3 chelates with CF2Cl2/O2 gas system. The chemical characteristics of the CVD products were considered from the thermochemical point of view.

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Abstract  

The isotopic ratios240Pu/239Pu in plutonium samples purified freshly and allowed to stand for a long time were determined by using a high resolution internal conversion electron spectrometer. As a result, it was proved that the above ratios can be determined accurately and precisely. The method was also examined further through a similar determination with curium samples.

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Abstract  

A new internal conversion electron spectrometer with high energy resolution has been developed using a windowless Si(Li) detector, and its characteristics are examined and discussed. As a result, it is confirmed that the energy resolutions are 0.48 keV in FWHM for 42 keV electrons and 1.43 keV for 624 keV electrons, respectively.

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Abstract  

Preparation of thin film deposits of lanthanide, thorium and uranium oxides has been studied by chemical vapor deposition (CVD) method using -diketonate metal chelates with 2,2,6,6-tetramethyl-3,5-heptanedione and some reactant gases as starting materials. The deposition process was carried out using a special apparatus designed for the CVD method at atmospheric pressure and temperatures as low as 400–600°C.As a result, it was demonstrated that each chelate used was well suited for the above purpose by its high volatility and reactivity with the reactant, especially with water vapor.

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Abstract  

An internal conversion electron spectrometer with high energy resolution has been constructed by using a windowless Si(Li) detector. After its characteristics were examined fundamentally, it was applied to determine the240Pu to239Pu isotope ratio. As a result, the energy resolution realized was demonstrated to be satisfactory.

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