[en] Questions whether the three laws for developing power resources have fulfilled their function for making the agreement with inhabitants, and the direction for strengthening the measures are discussed. The first part deals with the location problem of power plants. The most important reason why inhabitants refuse the public acceptance for nuclear power plants is the fear for safety and the hitherto nuclear national policy. Therefore, the adjacent area arrangement measures must be completed. The second part deals with the three laws for developing power resources now in force and the problems thereof. The tax for promoting the development of power resources amounts to about 33,200 million yen in 1977. The subsidy granted to the adjacent area for locating a power plant is for example about 3,500 million yen for a plant of 1 million kW output. Attentions must be paid to (1) the object facilities for the granted subsidy, (2) the time and term of granting subsidy, and (3) the fundamental plan for the adjacent area arrangement. The third part deals with the features of adjacent area arrangement for locating a nuclear power plant. The fourth part deals with the author's opinion for promoting such measures of the above described fundamental plan. The fundamental plan must be composed as follows: (1) the assessment of community, (2) the arrangement plan based on the direction of developing the economical society of the area, and (3) so called physical facility arrangement plan. (Iwakiri, K.)

[en] This report deals with the behavior of an SF₆ arc: a relation between a rotating speed and an arc current in a radial magnetic field created by a ring shaped permanent magnet. The experimental apparatus consists of a pair of cylindrical electrodes (CuW, 40m m outside dia., 30 m m inside dia., 46m m gap length), the permanent magnet and an insulating nozzle (PTFE, 25 mm inside dia.). They are arranged on the same axis in the SF₆ gas at a pressure of 3 ata. The calculated radial magnetic field distribution is shown. A resonant L-C circuit feeds the currents up to 20kA,rms at 60Hz. The arc is ignited with copper wire (0.1m m dia.). The arc motion is observed with a high speed framing camera in the axial and radial directions simultaneously. Each side of the arc near the electrode rotates in a direction opposite from each other, in the direction of the Lorentz force with almost the same speed. The rotating speed of the arc as a function of the instantaneous value (I_i) of the current is shown

[en] The electron cyclotron emission (ECE) spectrum at the large helical device (LHD) is measured by a 14-channel grating polychromator. During standard operation, the polychromator monitors second harmonic frequencies (100-150 GHz). At sufficient high density, the second harmonic X-mode polarisation is optically thick and can be used to determine the temperature profile. However, the large magnetic field shear in LHD affects the ECE polarisation. This effect has been studied numerically. The wave polarisation was found to rotate in the laboratory frame. Experiments have been carried out by means of a polarisation rotator in the diagnostic waveguide system, which confirmed the calculations. By a proper setting of the polarisation rotator, the rotation can be corrected and pure X-mode is detected. Temperature profiles have been measured successfully by the polychromator

[en] An electron cyclotron emission (ECE) diagnostic system has been installed on the large helical device (LHD). In LHD, the magnetic field profile has a peak near the plasma center, so the electron temperature profile of both sides can be continuously measured by the ECE system using two antennas. The ECE spectrometers are as follows, two heterodyne radiometers with the local frequency of 70 and 132 GHz, respectively, a grating polychromator and a Michelson spectrometer. The measurements are processed by the distributed data acquisition system. The angle of the magnetic field from the toroidal direction varies from -30 to +30 deg. in LHD. It is found that the polarization of ECE follows the angle of the magnetic field when the electron density is high enough. The effect of the polarization is considered when the temperature calibration is performed. ECE is useful to distinguish small perturbations in the electron temperature profile, for example, to effects of a local island diverter

[en] Next fusion research experiments plan to use many superconducting magnets. When a quench phenomenon is observed, the current should be interrupted to protect the magnet. Therefore, a dc circuit breaker is necessary. There are four technical situations to be considered for the dc circuit breaker system; (1) high rated current, (2) smaller size breaker, (3) high reliability and (4) no surge voltage during the interruption. The sizer of the breaker is limited by the arc current density of the contacts, and the low current density is better in the circuit breakers. A high rated current also needs the large contacts of the breaker. Here, we introduce a new type of dc circuit breaker system which does not generate an arc plasma between the contacts, equip the high rated current disconnecting switch and a fuse for the failure of the interruption, and use the conventional ac breaker. The switch size of the breaker is almost one hundred times smaller than that of the previous switch. (orig.)

[en] The electron cyclotron emission (ECE) spectrum at the Large Helical Device (LHD) is measured by a 14-channel grating polychromator. During standard operation the polychromator monitors 2nd harmonic frequencies (100-150 GHz) with a spectral resolution of 1.5 GHz. At sufficient high density the 2nd harmonic X-mode polarization is optically thick and can be used to determine the temperature profile. However, the large magnetic field shear in LHD affects the ECE polarization. This effect has been studied numerically. The wave polarization was found to rotate in the laboratory frame. Experiments have been carried out by means of a polarization rotator in the diagnostic waveguide system, which confirmed the calculations. By a proper setting of the polarization rotator, the rotation can be corrected and pure X-mode is detected. Temperature profiles have been measured successfully by the polychromator. (author)

[en] Electron cyclotron emission (ECE) can be used to determine the electron temperature profile in magnetized plasmas. The complex structure of the magnetic field configuration in the Large Helical Device (LHD), which has a large shear, complicates the analysis of the ECE spectrum. In a sheared magnetic field the propagation of X and O-mode polarization through the plasma are coupled, causing mode conversion and polarization rotation. Mode scrambling is also caused by wall reflections. In this report, this mode conversion in LHD is numerically analyzed. It was found that at low density mode conversion scrambles the ECE spectra. However, at higher density (n_eo > 1.0·10¹⁹ m^-3) the polarization mode is found to rotate with the sheared magnetic field, yielding only a negligible mode conversion. Wall reflections are found to depolarize the ECE spectrum. Notwithstanding the LHD magnetic configuration, it is shown that temperature profiles could be revealed from the ECE spectra. (author)

[en] Neutron optics has a potential to remarkably improve the performance of neutron scattering instruments. A superconducting sextupole magnet was constructed and characterized. The application of the magnetic optics to the small-angle neutron scattering with the focusing geometry is discussed

[en] The neutron focusing effect of a superconducting sextupole magnet has been investigated using unpolarized and polarized cold neutrons. The feasibility on the application of the magnetic lens to small-angle neutron scattering experiments are discussed

[en] The second harmonic X-mode electron cyclotron emission (ECE) from high-density plasma (the electron density is more than 50% of the cut-off density) is analyzed taking into account the refractive index and the influence of polarization in low field operated large helical device (LHD) (the magnetic field B₀=1.5 T). The density dependence of ECE is obtained and compared with the predictions of a theoretical model. It is concluded that the density dependence significantly influences the measurement of T_e by ECE in LHD