A rectangular pulse vertical field circuit of transistor type was devised and assembled as a substitute for usual crowbar type. The circuit is composed of 10 units, each consisting of a capacitor, a transistor and a comparator. The current rise time, the maximum field and the current duration of the circuit are 750A/ms, 18G and 2.5ms, respectively. When the pulse vertical field of the circuit having a short current fall time is applied on a plasma, the horizontal displacement of the plasma is reduced, the plasma is stably confined around the center of a vacuum vessel and the duration of plasma current is elongated. The rapidly rising pulse vertical field can clarify the effect of the vacuum vessel as a thin-casing shell.

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Axial and radial distributions of electron temperature and density in a conventional and a shielded vacuum arc deposition apparatus for TiN film fabrication were measured using Langmuir probe method, and intensities of spectra radiated from the plasma were also measured along the arc axis. Moreover, radial distributions of deposition rates were obtained.
The results obtained were as follows. (1) Electron temperature was constant of about 2 eV at any position. (2) Electron density drastically decreased behind the shield plate. (3) Spectral intensities of Ti⁺⁺ and Ti+ also decreased behind the shield plate, whereas those of Ti, N₂⁺, and N₂ were similar for both the conventional and the shielded arc. (4) Deposition rates at the position shadowed by the shield plate decreased, while similar deposition rate were obtained at the outer position for with and without shield plate.
From above results, particle behavior in the shielded arc was discussed as follows. Ti ions emitted toward the shield plate were trapped and shadowed by the shield plate although the electrons were not. As a result, behind the shield plate, Ti ions outside the shadow of the shield plate were attracted to the apparatus axis due to ambipolar diffusion between the ions and the electrons.

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A mechanism of the input-output hysteresis is analyzed for the magnetostrictive shaft torque sensor with phase-sensitive-detection technique. The origin of the hysteresis is the magnetic hysteresis between the applied torque and the permeability of the magnetostrictive shaft material, hence, the impedance of the pickup coil coupled to the shaft surface. The shape of the input-output hysteresis, which is the hysteresis of the output voltage converted from the impedance of the pickup coil by the phase-sensitive-detector, changes with excitation condition. Under a certain excitation condition, the input-output hysteresis becomes zero for the torque sensors constituted with a class of steel shafts.

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Basic characteristics of 3-dimensional Helmholtz coils for radiated immunity test have been studied. The coils can excite the magnetic fields of an arbitrary direction. By applying the fields to equipment under test (EUT), the immunity characteristics of EUT for the magnetic field of an arbitrary direction is made clear. Computer calculation is done to evaluate the field uniformity that is necessary for radiated immunity testing. Moreover, the experiment using the small prototype is done to verify the estimation. The results show that the excited field have the uniformity necessary for radiated immunity test.

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As a fundamental study for removal of nitrogen oxide by non-thermal plasma, the particle growth process is investigated in the pulsed positive corona discharge in the mixed gas of N₂, O₂, H₂O, NO and NH₃. From the ESCA and TEM analysis of sampled particles, the generated particles are confirmed to be NH₄NO₃. From the measurement of particle size distribution, it is clarified that i) the diameter of the generated particles distributes around the peak at about 50nm, and ii) an addition of water vapor enhances the particle growth. Because the NH₄NO₃ particle is deliquescent, it exist in a liquid phase in the humid air. The fact will cause the better NOx reduction efficiency and the larger particle growth due to the action liquid phase reaction in the humid air.

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For calculation of inductance of a linear electrode, vector potential is useful. If the electrode is in one of two media, a method of images is also useful. The paper presents a method of images for using vector potentials.
First, vector potential of a dipole composed of a linear current and two current sources in homogeneous medium is searched. Vector potentials of a semi-infinite linear current and a radiated flow plane current in homogeneous medium respectively, are also searched preliminarily. Then, images for representing the electric and magnetic fields of the dipole in one of two media are found by using the above vector potentials. Last, inductances of a horizontal and a vertical linear grounding electrodes in one of two media are computed by application of the above results.

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Wide spark discharge is necessary in order to dissociate ethylene (C2H4) gas in atmospheric pressure using the electron in the plasma. Then, it is possible that proposed floating multi-pole discharge drastically expanded the discharge region. This new electrical discharge method is very effective in order to decompose C₂H₄ gas.

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In Current Sustaining Tokamak in Nagoya university (CSTN)-IV research tokamak system using a compact 40kHz pulse width modulation (PWM) inverter power supply, which is controlled through LabVIEW program, we construct a new tokamak discharge system with multi-mode including a stable alternating current discharge and a high-repetition high-duty one. These discharge modes can be operated continuously for as long as 60sec. The continuous discharge with long duration is able to simulate the important physical and chemical processes of long time discharges in fusion devices, in which the heat load to the wall and the particle balance in the plasma-wall system are crucial topics in order to realize a long pulse fusion reactor, like ITER. Employing ergodic divertor (ED) is one of tools to control the particle balance and the heat load to the wall. In addition, we installed another inverter power supply to generate a rotating magnetic perturbation for dynamic ergodic divertor (DED) with the appropriate measurement system so that we may carry out experiments on heat and particle control with DED at long time operation.

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This paper deals with the theoretical analysis and experimental investigation of the modulation depth caused by Pockels effect in two Bi₁₂SiO₂₀ (BSO) crystals which have optical activity. At first, theoretical analysis was carried out by supposing the elliptical polarization caused by the Pockels effect passed through the BSO crystals in company with the rotation of the polarization plane caused by optical activity. Then, experiments were carried out using a single BSO and two BSO crystals placed successively, and compared with the calculated results. The BSO was 5mm in thickness and modulated with a longitudinally applied voltage. It was clarified that the experimental results agreed well with the calculated results. It was also clarified that the modulation depth of the two BSO crystals applied with opposite polarity voltage at the analyzer angle 0° was about 2.7 times higher than that of the single BSO, and this two BSO system was very effective against higher sensitivity of the optical voltage measurement.

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The location of a current dipole in human brain is obtained with good accuracy by using MEG. However, it is difficult to estimate a radial component of the dipole by MEG, because a shape of human head resembles to a sphere. We developed a novel MEG/EEG hybrid method based on the consideration of merits of MEG and EEG to estimate a current dipole with radial component. A simulation investigated the performance of this method. It was shown that the accuracy of the source localization by this method was better than the accuracy of the estimation by other methods such as usual MEG/EEG hybrid method. This method was also applied to the real MEG and EEG evoked by median nerve stimulation.

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Experiments were conducted to measure the space charge profiles in LDPE and XLPE dielectrics containing A.O (anti-oxidant) and surfactant. Only homocharge is detected in LDPE even when the material contains A.O. or surfactant. It is discovered that positive charge profile in the vicinity of positive electrode is greatly influenced by the density of LDPE, which suggests that the diffusion of positive charge injected from the positive electrode is dependent upon the crystallinity of LDPE. Negative heterocharge is detected in the vicinity of positive electrode in XLPE dielectrics containing PDP (peroxide decomposition products). The profile of the positive charge in XLPE was discovered to be dependent upon the containing A.O., which suggest generation of charged carriers due to the synergetic effect between PDP and the A.O.. The surfactant is also discovered to be influential to the space charge profile in LDPE.

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Cross-linked polyethylene (XLPE) cables are widely used for AC transmission. However, for DC tranmlssion, they are still under feasibility study due to severe concern about space charge. In the bulk of XLPE insulated cables, there remain chemicals such as acetophenone. We have examined the influence of acetophenone on the space charge evolution in PE. The samples tested are additive-free LDPE and LLDPE sheets. Two types of specimens were examined. The first one is a two-layered specimen consisting of a non-treated sheet and an acetophenone-soaked sheet. The second one is a LDPE or LLDPE sheet, onto which a few drops of acetophenone were spilt so that the sample surface was coated with acetophenone. The important conclusions obtained are as follows:(1) Positive charges are easy to migrate from the acetophenone-existing region to the non-existing region in the case of LDPE, while negative charges are difficult. (2) Both positive and negadve charges are rather immobile in LLDPE, and they tend to accumulate at the interface between the acetophenone-existing and non-existing regions. (3)The values of mobility and conductivity calculated from the space charge profile agree with the assumption that ionic carriers are responsible for the conduction in the acetophenone-existing region.

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In biomagnetic measurements such as magnetoencephalography and magnetocardiography, very weak magnetic fields have been measured. Magnetic sensitivity can be limited by microtremor of magnetically shielded room (MSR) used for the measurements as well as environmental magnetic noise at low frequencies caused by streetcars (trains), motorcars traffics and elevators. There are two possible mechanisms for a contribution of vibration of the MSR to magnetic noise: movements of the MSR shielding panels change magnetic field inside the MSR and the vibrating SQUID magnetic sensors receive static magnetic field as time-varying magnetic field.
Thus, it is important to investigate the relationship between magnetic noise and vibration of the MSR, and method for eliminating the vibration is desirable. In this paper, we measured the magnetic noise in the MSR using a 148-channel SQUID magnetometers (BTI) when artificial vibrations were applied to the MSR by means of heal impacts and evaluated correlation between the vibration and magnetic noise. Further an active microtremor isolation system (TACMI) was installed as a base of MSR to reduce the microtremor of the MSR. We also measured reduction of vibration and magnetic noise in an MSR actually mounted on TACMI.

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By rotating the floating multipole discharge at high speed, it was efficient in the atmosphere, and it became possible that the plasma was produced. The high voltage is applied to the electrode using the induction coil.

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