The calculation of scintillation spectra for the broad parallel γ rays emitted from ²³⁵U fission products incident on right circular Cylindrical Nal (Tl) crystals was presented. The detection efficiencies and photofractions of crystals were both taken from Miller, Reynold and Snow's works (1958). The procedures of the calculation were the same as those of the previous report (II). The typical figures of scintillation spectra from fission products were presented in both cases, one of which includes Compton continuum and the other does not. The parameters of the spectra were tabulated as functions of time after fission. The calculated spectra with a 1-3/4in. φ×1 in. crystal were practically same as those with the well type crystal which were referred in previous report (II). With a 4in. φ×4 in. crystal, however, the relative height of peaks in lower energy range, I, II and III, became lower whereas peak in higher energy range, X, became higher than those with a well type crystal. In another words all peaks tend to be equalized in relative height for larger crystals.
The samples of fission products, of which the data were presented in previous report (III), were measured with a 1-3/4in. φ×1 in. Nal (Tl) crystal and with 1 in. φ×1 in. anthracene crystal by both conventional and two-crystal scintillation spectrometers. In the latter, Compton continuum was automatically subtracted on recorded spectra. In general, the resolution of cylindrical crystals was better than that of well type, and so the more detailed structures were observable in the scintillation spectra with cylindrical crystals. Accordingly, to deduce the ages of fission products, the former was more useful than the latter.
Comparison of the experimentals with the calculated spectra shows a good agreement except at the peak I, II and V. The cause of said discrepancy was alraedy discussed in the previous report (III). In addition, the calculated spectrum was compared with other experimental spectrum. Although the conditions of the experiments were not always equal to the assumption for the calculation, there showed a rather good agreement between both spectra.

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A radiochemical study on the extraction behavior of about sixty chemical elements was performed in 3% DBSA, 1:1 diethyl ether ethyl acetate mixture, and hydrochloric acid solution system. The distribution ratios between organic and aqueous phases were determined in the acidity range 0.01 to 2.0_N hydrochloric acid. The characteristics of the acid dependence curves mentioned in the previous paper, viz.
(a) DBSA extraction gives different K_d values depending on the valency of the inorganic cation to be extracted;
(b) DBSA is of no use for anion extraction;
(c) K_d values in DBSA extraction are not so high or so low that determination of K_d values is easy;
were definitely confirmed in this study. In addition, the similarity between DBSA extraction and cation exchange was clarified. The usefulness of DBSA extraction in indicating the valency or ionic charge of inorganic cations in aqueous solution, was clearly ascertained.

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In ammonium carbonate-nitrate solution, U (VI) forms an orange colored precipitate, {[Co(NH₃)₆]NO₃}₂UO₂(CO₃)₃, with hexamminecobalt (III) chloride. The precipitate dissolved in diluted hydrochloric acid gives orange coloration due to hexamminecobalt (III) ion. In neutral or acidic solution the complex salt decomposes with sodium sulfide and yields cobaltous sulfide precipitate which is extractable with nitric acid.
Utilizing these properties, the indirect colorimetric determination of 0.02510.0mg U (VI) in two different ways: measurement of absorbance at 473mμ for hexamminecobalt (III) ion and the colorimetric determination of Co (II) ion contained in the precipitate. For hexamminecobalt (III) photometry, disturbance of the method caused by the presence of Ca, Ni, Co, Cu, Pb, Cd, Fe, Bi and Th were studied. Furthermore, a radiometric determination was devised for the estimation of 0.0050.500mg U (VI) with the ⁶⁰Co tagged precipitant.

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Zero-current and Polarity-effect of ionization chambers have been studied experimentally. The former turns out to be mainly from the contact potential difference between two electrodes. While, as for the latter, it was found that the zero-current of the output electrical connector of ionization chamber makes it most dominantly at ordinarily condition, and when it comes to lower pressure (<∼1mmHg) Taylor-Greening Effect becomes effective.
An effective range is introduced to understand the characteristics of ionization current at the “recombination region”.

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The author has quantitatively determined the thorium contents of some pitchblends from representative uranium ore deposits in France. The chemical analysis has been effectuated by the “anion exchange-T. T. A. extraction-spectrophotometry by thoron” method. The loss of thorium which happened to occur during the operations has been evaluated using UX₁ as radio-isotopic tracer.
The thorium contents ranged from several ppm to the order of 10ppm, and such values which are not so higher than those in granitic rocks show the immobility of thorium in the process of epi-hydrothermal mineralization of uranium in the granitic rocks.

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Anisotropic properties of cold and hot rolled plates were studied by the growth on thermal cycling, thermal expansion coefficients in rolling and transverse directions, and inverse pole figures in rolling plane.
Preferred orientation was found by a few percent reductions in thickness in cold or hot rolling. The difference between the thermal expansion coeffcients in rolling and transverse directions was increased with increasing the reduction, but was less in 550°C rolling than in room temperature or 300°C rollng. No essential difference in preferred orientation between room temperature and 300°C rolling was found and the results were well explained by those of M. H. Mueller, et al. The preferred orientation in 550°C rolling was also able to be explained by some components proposed by them. Namely, (7, 17, 19)-[110], the main component, and (4, 17, 20)-[410], one of minor components, were observed.

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Changes in crystal structure of three kinds of extruded Magnox (Magnox E, C and A 12) and Mg-1%Al alloys on heat treatment and tensile properties at room and elevated temperatures were investigated.
These alloys recrystallize about at 350°C and crystal grains of these alloys grow rapidly into heterogeneous coarse grains as increasing in temperature from 350°C. The growth rate of Magnox A12 grains is the most rapid and that of Be free Mg-1%Al alloy is the latest. Decrease in hardness and grain growth of these alloys except Magnox A12 have done in the first few hours at the temperature range from 300° to 450°C. Grains of Magnox A12 go on growing heterogeneously during at least 100hr. For example, grain size of 0.02mm at room temperature becomes 0.6mm after heating at 400°C for 62hr.
The results of the tensile test of extruded Magnox alloys at room temperature show 2224kg/mm² in U. T. S., 1215% in elongation, and brittle fracture. Strain age-hardening phenomenon is found in Magnox A12 and C. U. T. S. and elongation of these alloys annealed at 350° and 400°C for 100hr are smaller than those of as extruded condition. The results of the tensile test of extruded Magnox alloys at 350°C under the strain rate of 142.5622.5%/hr reveal 23kg/mm² in U. T. S., 60100% in elongation and the one is only a few affected by the strain rate, the other is little. These alloys show ductile fracture at 350°C without phenomenon of cavitation under the strain rate described above.

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This brief survey report presents the summary of neutron slowing down and diffusion measurements by pulsed neutron techniques.
This techniques have been successfully used for experimental study of reactor physics, especially diffusion problem, in past one decade.
In Chap. I, we shall summarize the theoretical approaches to the diffusion cooling effect and recent developments considering the influence of chemical binding energy. In Chap. II, we shall discuss the basic requirements for instruments and material arrangements. J. A. E. R. I. compact pulsed neutron source (Cockcroft type-200kV) and time analyser are shown as examples. In Chap. III, we shall survey the theoretical and experimental results for various moderator.

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