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The large helical device (LHD) is the world largest helical system having all superconducting coils. After completion of LHD in 1998, six experimental campaigns have been carried out successfully. The maximum stored energy, central electron temperature, and volume averaged beta value are 1.16 MJ, 10 keV, and 3.2%, respectively. The confinement time of the LHD plasma appears to be equivalent to that of tokamaks. One of the most important missions for LHD is to prove steady-state operation, which is also significant to international thermonuclear experimental reactor (ITER) and to future fusion reactors. LHD is quite appropriate for this purpose based upon the beneficial feature of a helical system, that is, no necessity of the plasma current. So far, the plasma discharge duration was achieved up to 150 s. The plasma density was kept constant by feedback control of gas puffing with real time information of the line density. The issue for demonstrating steady-state operation is whether divertor function to control particle and heat flux is effective enough. Relevant to this, LHD diagnostics should be consistent with the following: 1) continuous operation of main diagnostics during long-pulse operation for feedback control and physics understanding; 2) measurement of fraction of H, He, and impurities in the plasma; 3) heat removal and measure against possible damage or surface erosion of diagnostic components inside of the vacuum chamber; 4) data acquisition system for handling real time data display and a huge amount of data. Although there are already some achievements on the above subjects, there remain still several issues to be resolved. On the other hand, the long-pulse operation of the plasma gives benefits to the diagnostics. For example, the polarizing angle of ECE emission can be changed during the discharge, and the intensity dependence on the polarizing angle has been obtained. The spatial scanning of the neutral particle analyzer and the spectrometer can supply the spatial profiles of the fast neutral particle flux and the specific impurity lines. In this paper, the present status of these issues and future plans are described.

Assessment skills to determine cognitive function and functional ability are important to maintain the quality of care. In analyzing movement patterns of the subjects in our pilot study, we found an unusual pattern of frequent trips to the toilet by one subject. An IC tag monitoring system could be used to assist staff to identify patients with unusual movement patterns and so improve safety and quality of care.

Diagnostics in infrared and far-infrared range for Heliotron E are described; (a) FIR interferometer for measuring electron density profile and (b) ECE for electron temperature profile as routine work, and (c) Fraunhofer diffraction method with a CO/sub 2/ laser for density fluctuation and (d) Thomson scattering with a D/sub z/O laser (/spl lambda/ = 385 /spl mu/m) for Ion temperature, as new methods.

The next innovation in the power modules has come up with the corroboration between the power chip technology like CSTBT and die packaging technology like the direct transfer mold module, via wireless bonding technology, that is our technology "direct beam lead bonding (DBLB)". In this paper, we report the electrical characteristics and the reliabilities of a MOSFET and a CSTBT using DBLB. The DBLB type MOSFETs on-state resistance (R/sub DS(GN)/) can be reduced in 16% comparing with die conventional aluminum (Al) wire bonding type and an avalanche ruggedness (E/sub AVA/) during undamped inductive switching (UIS) is unproved approximately 2 times. It has the excellent reliability under the thermal cycling test between 233K and 398K during over 3000 cycles. Further, the DBLB type CSTBT has, under the short circuit safety operation area (SCSOA) test condition, 11% greater toughness as energy than the Al wiring type.

Summary form only given, as follows. The Large Helical Device, LHD, is the world largest helical system having all superconducting coils. After completion of LHD in 1998, 6 experimental campaigns have been carried out successfully. The maximum stored energy, electron temperature, and beta value are 1.2 MJ, 10 keV, 3.2 %, respectively. The confinement time of the LHD plasma appears to be equivalent to that, of tokamaks. One of the most important missions for LHD is to prove steady state operation, which is also significant to ITER and to future fusion reactors. LHD is quite appropriate for this purpose based upon the beneficial feature of a helical system, that is, no necessity of the plasma current. So far, the plasma discharge duration was achieved up to 127 sec. The plasma density was kept constant by feedback control of gas puffing with real time information of the line density. The issue for demonstrating steady state operation is whether divertor function to control particle and heat flux is effective enough.

Optimized self-aligned transistors for low-power ECL (emitter-coupled-logic) circuit applications are discussed. The ECL circuit was fabricated using a 0.5- mu m rule and a 28-GHz f/sub T/ technology and evaluated in terms of the propagation delay time of ring oscillators and a 1/8 static divider. The analysis of the circuit, the process design, and the npn transistor structure are discussed. A 39-ps/1.6-mW ECL circuit and a 12.5-GHz 1/8 static divider were obtained. >

From the results of the simulation study including pellet ablation and 1-D transport code, it is found that a high speed pellet injector with pellet velocity of more than 3 km/s is necessary for the penetration of the pellet with diameter of 3 mm into the core region under the expected plasma condition of Large Helical Device (LHD) of heliotron/stellarator type with superconducting coils at NIFS in Japan. Therefore, a two stage pellet injector was constructed and tested successfully in order to obtain the pellet velocity range of 3 km/s. Based upon the above results, a high speed flexible multiple-pellet injection system "HIPEL" for LHD is proposed. HIPEL consists of independent (1) 10 two-stage gun barrels and (2) 10 single-stage gun barrels. It has multi purposes such as refueling and flexible density profile control, diagnostics and the other functions.

Prototype continuous pellet injector has been designed and is under construction for the Large Helical Device at National Institute for Fusion Science in Japan. This injector is a centrifuge type, aiming at long-pulse pellet injection. A centrifuge pellet injector is a mechanical device that utilizes centrifugal force to accelerate solid hydrogen-isotope pellets using a high-speed rotating rotor. The injector consists of a hydrogen-isotope filament extruder, a pellet forming device, and a pellet accelerator. It is expected that pellets of 1 mm and 1.5 mm in diameter and length will be accelerated up to 800 m/sec in this system.

Deuterium pellet injection is used for investigation of transport of Heliotron E plasmas through a dynamic process. With an ECH (electron cyclotron heating) heated plasma as a target plasma, such conditions as auxiliary toroidal field control, magnetic axis shift, and externally added magnetic field perturbation are studied. Among various magnetic axis positions from delta /sub v/=-60 mm to delta /sub v/=+35 mm, cases from delta /sub v/=-40 mm to delta /sub v/=0 mm are found to be good for confinement. In the gas puffed case, delta /sub v/=-20 mm was optimum. In the case of alpha *=0.05 and delta /sub v/=-20 mm, the ECH plasma seems optimum. The line-averaged density in the central chord after pellet injection is kept constant even without gas puffing in contrast with cases of alpha *=0.0. In the experiments on magnetic field disturbance, only a small difference between MI=0% and MI=100% under the standard configuration is observed, which is consistent with the results obtained by gas puffing. >

Hydrogen pellets without sabots were accelerated to high speeds using a two-stage light gas gun for Heliotron-E. The primary application of this technology is plasma fueling of fusion devices. Conventional pellet injectors have limited pellet speeds in the range of 1-2 km/s. Higher velocities are desirable for more flexible density profile control and for deep penetration into a high-temperature plasma. By developing a new fast valve with high conductance to accelerate the piston and other components, a 2-mm-diam hydrogen pellet with a velocity of 3.2 km/s has been successfully accelerated without a sabot. The pipe gun technique for freezing hydrogen operation is simulated with the code MYKE. Development of new pistons instead of the plastic piston for the repetitive two-stage pellet injector is being carried out using metal and ceramic, as the surface of the plastic piston tends to wear out through repetitive operation and carbon powder produced from the plastic piston may cause trouble with the fusion device. >

Research on the growth and applications of single-crystal fibers in Japan is reviewed. Currently, three growth methods for single-crystal fiber preparation are being investigated in Japan: the laser-heated pedestal growth (LHPG) method, the micro-Czochralski method and the crucible method. The application of the device to second-harmonic generators, miniature solid-state lasers, and optic sensors is described. >

Interdiffusion of arsenic and phosphorus at InGaAs/InP interfaces causes degradation of hetero-interface abruptness. This problem limits the use of thin quantum wells (QWs) in this material system. Previously, we studied the As-P exchange process at the interface between InGaAs and InP in metal-organic vapor phase epitaxy (MOVPE) by using in-situ kinetic ellipsometry. We have studied here how the information from the in-situ kinetic ellipsometry could be utilized to optimize the growth condition and to secure the hetero-interface abruptness in InGaAs/InP QWs. As a results, we could improve hetero-interface abruptness by two different ways that the in-situ kinetic ellipsometry results suggested.

The synthesis method of active low pass filters using uniformly distributed RC line has been published. This paper describes the Low Pass Filter (LPF) using double capacitive layers uniformly distributed RC line (DURC). This LPF circuit configuration with notch characteristics consists of DURC and a positive gain amplifier. The LPF using DURC can be used for anti-aliasing/smoothing filters for signal processors.

All industries have started to conduct research in environmentally safe materials. In the electronics industry also environmental issue is one of the most important concerns being addressed with rapid technical improvement. Flame retardant agents like halogen and antimony oxide are used in plastic molding compounds to provide flame retardant characteristics to all plastic encapsulated packages. However these materials have concerns as they are considered environmental hazards. This paper deals with the study of a new environmentally safe flame retardant system for plastic encapsulants. We studied the application of a new non halogen and non antimony oxide flame retardant system for the molding compound of Ball Grid Arrays (BGA) as the next generation conventional standard package.

In InGaAs/InP heterostructures, interdiffusion of arsenic and phosphorus at the hetero interfaces (As-P exchange) during epitaxial growth degrades the interface abruptness. This is a significant problem when a very thin InGaAs/InP quantum well is required. In this paper, a spectroscopic and kinetic ellipsometry is used to monitor the As-P exchange in-situ in metal-organic vapor phase epitaxy (MOVPE) with TBAs and TBP as group V precursors. As a result, it is found that the monitoring of As-P exchange is possible by kinetic ellipsometry and that useful information to improve gas switching sequence is acquired from such observation. An InGaAs/InP quantum well grown by making use of such information has exhibited the best photoluminescence characteristics.

A new method for measuring the actual coupling coefficient of a split-gate flash EEPROM whose floating gate voltage is controlled by the source voltage is presented, which uses no additional test structure or nonfloating gate TEG. In this method, the subthreshold current is measured twice as the source voltage is increased after the control gate transistor has turned on sufficiently. After the drain voltage is slightly altered (/spl Delta/V), the subthreshold curve is a/spl middot//spl Delta/V shifted from the previous one. The coefficient a obtained by this method agrees with the value obtained by the well known subthreshold slope method using a test structure.