[en] Paper presents a procedure to estimate the radon emanation coefficients for UO₂ particles deposited on the surfaces of the uranium-containing waste. For the mentioned conditions and on the basis of the available information on the dispersion spectrum of UO₂ particles the emanation coefficients of walls, equipment and vent filters is estimated to constitute 0.03. In real situations the uranium-containing waste is exposed to decontamination making difficult to evaluate the emanation coefficient. The conservative value of the emanation coefficients equal to 0.5 is recommended to be used for the mentioned conditions

[en] Boron segregation and precipitates were investigated using EFTEM. Chromium borides were identified. Comparison with published results suggests that segregation is mainly of non-equilibrium type. Non-uniform distribution of precipitates can be explained using nucleation theory if the segregation leads to grain-boundary boron concentration only slightly above the solubility limit

[en] In order to examine the accessibility of the high-frequency heating of plasma in the lower hybrid frequency range, the interactions between the high-frequency electromagnetic field and a highly ionized plasma were studied. In the case of the low power the absorption coefficients were measured, while in the case of the high power the changes of the energy density of plasma were examined. These experimental observations are compared with the theory of the linear mode conversion

[en] Bromine-81 and aluminum-27 nuclear quadrupole resonance (NQR) data have been obtained for a series of MAl₂Br₇ compounds (M = NH₄, (CH₃)₄N, and (C₂H₅)₄N). For the cation change from (C₂H₅)₄N⁺ to NH₄⁺, the bridging ⁸¹Br NQR frequency increases about 10 MHz, which is about 13% of that in the (C₂H₅)₄NAl₂Br₇ compound and too large to arise from only crystal field effects. This large frequency shift is suggestive of the polarization of the anion induced by neighboring cations. That is, the negative charges of the anion are more localized at the terminal positions than at the bridging position with increasing polarizing power of the cation. The nuclear quadrupole coupling constants of ²⁷Al increase with increasing cation radius. This finding also supports the anion polarization model. 18 references, 3 figures, 2 tables

[en] Experiments of the interaction between the waves near the LHR frequency range and the plasma have been done in the octopole Tokamak of Nagoya University. Matching for the rf source was performed with a stub tuner and a phase shifter inserted between the rf source and the T-shaped antenna loaded with alumina. Data for this matching are furnished with mini-computor. The field sensitive rf probe located around 120⁰ apart from the exciting antenna in the toroidal direction gives decay like spectrum which has some correlation with the position of the plasma column

No abstract available

No abstract available

No abstract available

[en] A stochastic magnetic field either spontaneously excited or externally generated at the Tokamak edge leads to a predominant transport of electrons, which makes the bulk plasma potential positive. In this circumstance the acceleration of electrons by r.f. waves enhances the potential formation. (author)

No abstract available