Nine Technical Committees (TC's) of the Fundamentals and Materials Society of IEE Japan have contributed their Review & Forecast articles to the present. Special Issue of the IEEJ Transaction on Fundamentals and Materials. So you can survey the state-of-the-art of the 9 different technical fields with these articles. The series of reviews were submitted in reply to the request by experts in the respective fields.

抄録全体を表示

Rapid progress of information and communication technologies has been changing the education method. In Japan, online lectures have been recognized as the credits for graduation by the change of a law since 2001. One trial to construct an IT based learning system has been done for the development of IT based higher education and training. Educational effect of online lecture taken anytime and anywhere is evaluated, and then an authoring software for online lectures is developed for educators who are not familiar to IT. A learning management system begins to be operated for whole lectures, and a wireless LAN system is equipped in whole campus of Kumamoto University.

抄録全体を表示

In recent years, synchrotron radiation (SR) and free-electron lasers (FELs) have been playing an important role for the radiation sources in the region of the ultraviolet (UV) and X-ray wavelengths. From the viewpoint of classical electrodynamics, this article briefly reviews the basic principles of synchrotron radiation and free-electron lasers. In particular, special attention is paid to research efforts in the UV and X-ray free-electron lasers.

抄録全体を表示

Based on the survey of the papers and their topics presented at the latest international symposia on electromagnetic compatibility (EMC), a technical trend on EMC technology was described. The major trends include printed circuit board and integrated circuit related EMC problems, numerical modeling, statistical measurement and design, and human exposure, which should be selected as significant topics at the coming EMC international symposia.

抄録全体を表示

Power semiconductors have been applied to pulsed power generators, bringing new extent of capability in repetition rate, lifetime, compactness, and mobility to pulsed power sources. This development is accelerated in the last several years driven by the industrial applications such as excimer-laser excitation, flue-gas treatment, and accelerator power supply.

抄録全体を表示

Three topics related to the field of the technical committee on electrical discharges (TC-ED) are summarized for this special issue. First one deals with the protection against the lightning damages. As the second one, a prototype high voltage vacuum interrupter is introduced. The last one shows the problem on the electromagnetic relays.

抄録全体を表示

The technology on light application and visual science is widely applied in fields such as medical treatment, media devices for information processing of visual sense, light sources and their measurement, application of infrared ray, and fine lithography. In this paper, topics in the fields of infrared environmental monitoring and new light sources are introduced.

抄録全体を表示

Most of the clutter received by L, S, C, X, and Ku band radars obeys a Weibull ditribution. To suppress such Weibull-distributed sea and weather clutter, Weibull CFAR techniques are applied to data taken by an X-band radar using computer in real time. The results show the usefulness of Weibull CFAR.

抄録全体を表示

This article reports the state-of-art of TC-DEI ( Technical Committee of Dielectrics and Electrical Insulation of IEEJ) activites. The activiteis are basically based on the activites of 8-10 investigation committees under TC-DEI. Recent activites were categorized into three functions in this article and remarkable activity or trend for each category is mentioned as was done in the article of 2003. Thoese are activities on asset management (AI application and insulation diagnosis), activities on new insulating and functional materials (Nano composite) and activities on new insulation technology for power tansmission (high Tc superconducting cable insulation).

抄録全体を表示

Advanced-functional meatl andceramics sholed be progressed and created on the basis of cahracteristic length such as the Fermi wave length, the mean free path, the coherent length etc. These lengthes have themselves for each material. In this paper, needs diversification, reconsideration of conductivity, carbon polymorphisms, nano-structure in superconductivity will be reviewed and forecasted.

抄録全体を表示

Two types of conducted noise suppressors, which dissipate noise current energy before radiated as noise waves, were developed using Ni-Zn ferrite films synthesized from an aqueous solution. In the “sheet type," Ni-Zn ferrite films of 5 μm thickness were deposited on polyimide sheets. In the “direct-deposition type," the films were deposited directly on to the microstrip line fabricated on printed circuit board (PCB). The transmission loss ΔP_lossper thickness for the “sheet type" and “direct-deposition type" were 16 and 20 times larger, respectively, than that for commercialized composite noise suppressing sheets. Both types of ferrite-film noise suppressors exhibited reflection coefficient S₁₁ small enough (< -10 dB) to be applied as conducted noise suppressors up to 10 GHz.

抄録全体を表示

A repetitive pulsed high current generator has been developed and tested. It has been developed for generation of high-density plasma as an extreme ultraviolet (EUV) source. This generator has a peak output of current over 40 kA with a pulse width of less than 400 ns. The generator consists of a semiconductor switch and a magnetic pulse compression (MPC) unit. This paper reports the design details of the circuit and the magnetic switches.

抄録全体を表示

Temporal variation of electron energy distribution through a pulsed inductively coupled nitrogen plasma is discussed by the temporally resolved measurements of optical emission spectroscopy and laser-induced fluorescence. The intense intensity peak of the first negative band emission (N₂⁺) immediately after RF power application to the plasma is likely to be caused by the rapid increase and subsequent decrease in a ≈3-eV electron population because the electron impact excitation of ground state N₂⁺ ions is assumed to cause the first negative band emission. The intensity peak for the second positive band emission (N₂), the threshold energy of which is ≈11 eV, is also observed but even smaller than the first negative band emission, indicating the smaller enhancement of an electron population at ≈11 eV than that at ≈3 eV during electron heating after the RF power application.

抄録全体を表示

Copper nanosized powders have been prepared by pulsed wire discharge (PWD). The charging voltage and ambient gas pressure dependence on the particle size distribution has been investigated. The particle size ranged from 10 to 100 nm, and the distribution profile agreed with that of log-normal distribution. The median diameter decreased with the decrease in the ambient gas pressure, but did not change on the charging voltage.

抄録全体を表示

ESD (Electrostatic discharge) testing is becoming an indispensable item to test the immunity of electronic and information equipment. In taking effective ESD countermeasure in the early design stage of electronic products, a computer simulation technique for the ESD testing is being desired as a useful and powerful tool. From this perspective, we previously developed a finite-difference time-domain (FDTD) proto-type model for simulating the contact discharge of a commercially available ESD-gun with specification of the IEC61000-4-2 standard, and validated its effectiveness for the contact discharge to a 50-Ohm SMA connector, although only the simple skeleton structure of the ESD-gun was numerically modeled in the proto-type. In the present study, we improved the previous FDTD modeling to realize a more realistic ESD-gun for accurate simulation, and examined the effects of the structure modeling and the plastic covering used in the gun on ESD simulation. As a result, we found that the precise structure modeling of the ESD-gun gives good agreement of the contact discharge simulation with the measurement, while the covering does not almost affect the simulation. With the improved FDTD model, we then simulated an ESD testing for a printed circuit board (PCB) with the same sized metal surface on the back. A 50-Ohm micro-strip line fabricated on each of the PCB was modeled, and was excited in contact to the sending end with the ESD-gun. We found that there is good agreement between the simulation and the measurement for the induced voltages appearing in the receiving end of the micro-strip line.

抄録全体を表示

We have been examining the effects of superposition of a high-frequency voltage to various voltages such as dc, low-frequency (0.1 to 5 Hz), and power-frequency voltages on the development of water trees in polyethylene. We have made clear that the number of voltage zero-crossings is a decisive factor in the length of water trees. In the present research, the water tree shapes grown under the various superposed voltages were carefully observed. As a result, the water tree tends to become a hand-like shape if the frequency of the lower-frequency component is between 0 and 0.5 Hz, while it becomes spherical if the frequency is higher than 1.0 Hz. This result is explained by assuming that the water tree shape is governed by the number of consecutive voltage zero-crossings. By combining the results reported in our former papers, it can be concluded that the voltage zero- crossing is a decisive factor for the formation of water trees. Frequent mechanical oscillation at the tree tip due to the Maxwell stress should play a significant role.

抄録全体を表示

We have already three gas insulated power lines in service applying SF₆/N₂ gas mixtures, the two in Europe and the rest in South Asia. To cope with the global warming issue on gas insulated power apparatus, we have been investigating the recovery of SF₆ from those apparatus. This paper describes an automated gas recovery method that secures SF₆ gas concentration in the recovered gas at a high and desired level. The gas mixtures investigated contain 5 - 20 vol. % of SF₆ in N₂. We adopt a membrane method to separate the two gas species, in which two membrane separators are connected in cascade. There are several factors that affect the concentration of SF₆ in the recovered gas. As the concentration greatly depends on recovery gas flow speed, we control the speed by using a piezo-valve. For driving the piezo-valve, we use a voltage regulator together with an infrared gas concentration online monitor. This link allows PID control of the SF₆ gas recovery system. Successful operation results of this automated system, as well as the basic recovering characteristics of the cascaded system, are demonstrated after a brief review on gas recovery methods.

抄録全体を表示

If the magnetic field in a magnetic device which is operated at high temperature, for example 100 °C, is analyzed using magnetic characteristics at a room temperature ( RT ), there occur some errors. Although the measurement method using a single sheet tester ( SST ) has advantages that the material characteristics can be measured precisely, the research about the correlation between the temperature and the magnetic characteristics using SST is few. In this paper, firstly, the temperature characteristics of magnetic properties of silicon steel sheet were measured using SST, then, the temperature characteristics of the iron loss of the permanent magnet motor were estimated by using the finite element method ( FEM ). It is shown that the permeability is increased at low flux density, and decreased at high flux density when the temperature is increased. The iron loss is decreased similarly in almost all range of B_m. The change of iron loss is remarkable in the low grade steel ( 50A1300 ). The iron loss of SPM motor at 100 °C is decreased by about 10-20 % compared with that at RT.

抄録全体を表示

We have developed a precise sub-μm processing method by combining ion implantation and nano-plating. In order to show the applicability of this method, we have fabricated a mask for a Bragg grating, which has a striped gold structure with a height of 1.2 μm and a period of 1.59 μm on a 2-μm thick SiN membrane. We have also confirmed that the mask pattern can be transferred inside a silica glass by ion implantation. It is expected that this result can be utilized for the fabrication of optical communication devices.

抄録全体を表示

We investigate the insulation properties of CO₂ gas in the presence of a metallic particle. CO₂ gas attracts attention as an alternative gas to SF₆ gas because of its relatively very small global warming coefficient gas and relatively good dielectric strength. To design CO₂ gas-insulated apparatus, the influence of a metallic particle on insulation properties has to be clarified. In this paper, we investigate the motion of a metallic particle and partial discharges in CO₂ and SF₆ gases by measuring acoustic and electromagnetic signals. As a result, it was found that a free metallic particle motion differs in CO₂ gas and SF₆ gas because of differences in partial discharge characteristics.

抄録全体を表示