No abstract available

[en] Outlined are the following: 1.Features of Fuel Design; 2.Basic Design Parameters; 3.Basic Consideration in Fuel Rod Design; 4.Basic Concept of Core Control; 5.Monitoring of Power Distribution and Burn-up in Operation; 6.Operating Experience

[en] The reflection and transmission properties of electromagnetic waves by a semi-infinite uniaxial plasma moving perpendicular to the plane of incidence are investigated theoretically for the incident H and E plane wave. In this case, the plasma becomes anisotropic, and electromagnetic field components of the transmitted wave should be hybrid modes. Thus it is shown that the behavior of the power reflection coefficient is remarkably different from that of a stationary one

[en] An important issue in the application of high-T_c superconductors is thin film preparation. One of the most versatile methods for obtaining the thin films of YBa₂Cu₃O_x, so called 123 structure, is pulsed laser deposition (PLD). By PLD, we have prepared the 123 films grown epitaxially on the (001) and (110) of SrTiO₃. On the (110), epitaxial temperature can be lowered to 530 C without the assistance of reactive gases and plasma. The structure of the films has been studied by X-ray diffraction, Rutherford backscattering spectroscopy including channeling, reflection high energy electron diffraction, and transmission electron microscopy. In order to achieve an in situ formation of the superconducting films, the enrichment of oxygen content (x) as well as the crystal growth of the 123 structure is critical. It is demonstrated that in situ oxygen content control can be performed by the deposition and the subsequent fast cooling process without any post-treatments. The (001)-oriented thin films with x from 6 to 7 enable us to investigate the x dependence of electric conduction in the direction parallel to the CuO₂ plane, in which superconducting current is believed to flow. The results show that the properties of the ab plane of the YBa₂Cu₃O_x films resemble those of La_2-ySr_yCuO₄ films rather than YBa₂Cu₃O_x polycrystals. Moreover, it is concluded that YBa₂Cu₃O_x is in an over-hole-doping state at x near 7 in contrast to the common belief. (orig.)

[en] The dynamic behavior of the JT-60 vacuum vessel was examined during its power tests to confirm the validity of the dynamic response analyses of the vacuum vessel. The JT-60 power tests were carried out from December 1984 to February 1985 to demonstrate, in advance of actual plasma operation, satisfactory performance of the tokamak machine, power suppliers, and the control system working together. Special emphasis was placed on confirming the mechanical integrity of the tokamak machine under the designed full-power operation conditions. Noticeable vibration of the vacuum vessel was observed in the power tests. Dynamic response analyses showed that the vibration mode with the natural frequency of 46.3 Hz had a displacement amplitude of ∼ 0.1 mm at the rigid ring under the misfire startup operating conditions, which corresponded to the operating conditions during the power tests. The difference between the vibration amplitude of the rigid ring obtained in the dynamic response analyses and that observed at the lateral port was explained by the lever ratio effect of the lateral port. The validity of the dynamic response analyses of the vacuum vessel was confirmed through vibration monitoring at the lateral ports attached directly to the rigid ring during power tests

[en] Capture and scattering probabilities for neutrons impinging on thick samples were measured by the Japan Atomic Energy Research Institute Linac time-of-flight spectrometer and were compared with those by Monte Carlo calculation. Sweeping the indicent neutron energy, the capture probability shows peaks at resonance energies in the case of a thin sample, whereas it shows dips for a thick sample, i.e., saturation occurs just at resonance energies. This saturation phenomenon is analyzed by Monte Carlo calculation for a distribution of path lengths of incident neutrons in the sample until capture in the sample. The saturation values of capture probability at resonance energies P/sub co/ are defined, and their dependence on the resonance parameters GAMMA/sub n//GAMMA is examined. The relations between P/sub co/ and GAMMA/sub n//GAMMA, with parameters including recoil energy, are obtained by Monte Carlo calculation. The relations are verified by measurement of P/sub co/ for many resonances of various GAMMA/sub n//GAMMA values. With the relation, GAMMA/sub n//GAMMA can be determined from P/sub co/, which is not sensitive to sample thickness

[en] The design bending stress criterion of the JT-60 coil conductor are described. The relationship between loads and deformations for a conductor subjected to an axial and a lateral loads is taken into consideration in the stress analysis and the collapse load and true strain are calculated by the derived equations. It is clear from the analysis results that the materials with yield-tensile ratio more than 0.5 have a safety factor of 3 and those with yield-tensile ratio less than 0.5 have a higher safety factor than 3 when the coils are designed in accordance with ASME section III. In the JT-60 coil, the design value has sufficient safety factor higher than 3, which may guarantee the reliability of the coil. The present analysis may be applicable not only to the copper conductors but also to the other materials such as steel. (author)

[en] Saturation capture probabilities for neutrons, impinging onto thick samples at resonance energies, are proposed as a standard for capture probability, in the energy region of a few hundred eV. Capture probabilities for the 132 eV resonance of cobalt, are examined. (orig.)

[en] Recoil energies and effective masses of Fe, Cu, Mo and Sb are determined from the neutron capture line shapes for narrow resonances in rather thick samples, in which resonance capture without scattering and that after one scattering are predominant. Mass numbers obtained are consistent with the values of free atoms within experimental errors. (Auth.)

No abstract available