Search Results

You are looking at 1 - 10 of 20 items for

  • Author or Editor: T. Mitsugashira x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

Cu-di-(2-ethylhexyl)phosphate was used as the cation exchange extractant from molten nitrate salt. IR absorption spectra of di-(2-ethylhexyl)phosphoric acid and Cu-di-(2-ethylhexyl)phosphate were compared and it was proved that the acidic form of the extractant is not Cu-di-(2-ethylhexyl)-phosphate. Using LiNO3−NH4NO3 eutectic melt, it was shown that the back-extraction of Cu2+ is a cation exchange reaction. Np(V) and Pa(V) were extracted by Cu-di-(2-ethylhexyl)phosphate from LiNO3−NaNO3−KNO3 eutectic melt. The distribution ratio of Np(V) was greater than that of Pa(V) on the contrary of their distribution ratios in the aqueous extraction system. A possible cation exchange extraction reaction was proposed for the extraction of Np(V).

Restricted access

Abstract  

A method is proposed for the resolution enhancement transformation (RET) of the γ-ray spectrum, which is not only a simple convolution operation but also have a definite analytical significance because of the introduction of the parameter ω representing the degree of the resolution enhancement. We apply the RET to the peak detection method for complex overlapping peaks. The validity of this method is ascertained by the analysis of X-ray overlapping peaks.

Restricted access
Journal of Radioanalytical and Nuclear Chemistry
Authors: H. Yuki, K. Nakazawa, T. Ohtsuki, J. Kasagi, and T. Mitsugashira

Abstract  

Low-lying excited levels of231Th fed through α-decay of235U were investigated by using α-γ and γ-γ coincidence technique. From the analyses for co-relating energy levels and transition intensities, we found that the most favorable transition from 205.3 keV ([631]7/2) level that is fed by the most dominant α transition from235U is 19.6 keV transition (205.3 keV [631]7/2→185.7 keV [631]5/2). We also found that the transition probability of 109.2 keV, 205.3 keV [631]7/2→96.1 keV [633]9/2+, was corrected to be weak. These findings can explain why the 185.7 keV γ-ray is so strongly observed, 0.57 photons/ga, in the γ-spectrum associated with the α-decay of235U. The decay scheme of231Th levels previously reported has been modified according to the present analysis.

Restricted access

Abstract  

The11C and14C labeled fullerenes were produced by charged-particle and neutron irradiation, of C60, C70 and their mixture. It was found that a carbon atom of fullerence can be easily exchanged with a radioactive carbon atom produced by a nuclear reaction. The HPLC method was effective for identification and purification of various labeled fullerene families as chemically stable compounds. The radiochemically interesting aspect of the results is not only the production of11C and14C labeled fullerenes but also the formation of radioactive higher fullerenes which can be simultaneously produced with high yield and in carrier-free form.

Restricted access

Abstract  

Although application of the sum peak method to determine the PAC parameter
\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$\overline {G_{22} }$$ \end{document}
was limited to point source like specimens, a theoretical consideration has been made to examine the possibility of application of the sum peak method to specimens with finite dimension in this work. It has been revealed that the sum peak method can be applied to those specimens in the same manner as to point source like ones. Furthermore, the possibility of application of the sum peak method to determinations of the time differential attenuation factor G22/t/ has been discussed, and its procedure has been proposed.
Restricted access

Abstract  

Uranium and thorium isotopes were determined in highly pure aluminum for LSI fabrication by alpha-spectrometry utilizing natural 147Sm as an inner standard. Daughter nuclides in natural decay series are found in an enrichment state from radioactive equilibrium. Unexpected contamination that had a ground water origin was supposed to explain the enrichment. This finding suggests strongly that alpha-spectrometry is still quite an important technique to evaluate soft-error probability for modern memory device materials since highly sensitive instrumental analysis such as ICP-MS is not sensitive enough to short-lived alpha-emitters.

Restricted access

Abstract  

The normal concentration levels of trace metals in several kinds of tissues of even-toed ungulates have been determined by instrumental neutron activation analysis, photon activation analysis, and flame atomic absorption spectrometry. In the present work the concentrations of 13 elements (Ag, Br, Ca, Co, Cu, Fe, Mg, Mn, Mo, Na, Rb, Se, and Zn) were analyzed.

Restricted access

Abstract  

A random pulse and probability generator (RPG) has been developed utilizing the detection technique of alpha-particles as the random signal source. The collection technique for 222Rn emanated from natural uranium ore was examined for preparing highly pure 210Pb-210Po as an alpha source for RPG. The yield with a trap refrigerated by liquid nitrogen was observed to be above 99% for 222Rn collection.

Restricted access

Abstract  

Radiopolarographic reduction of Ac(III) was investigated in aqueous solutions. It was found that a very large shift of the half-wave potential was induced by the addition of 1, 4, 7, 10, 13, 16-hexaoxacyclooctadecane (18-CROWN-6) to the aqueous solution. The shift was explained by complex formation of Ac(II) with 18-CROWN-6. The ionic radius and the electronic configuration of Ac2+ were determined to be 1.25 Å and [Rn] 6d1.

Restricted access