Keiji Arimatsu

Development and Interrupting Tests on 250KV 8KA HVDC Circuit Breaker

This paper describes the circuit and component selections, development and equivalent circuit test results on an HVDC circuit breaker for an HVDC transmission line. A puffer type SF6 gas interrupter for AC circuit breakers is utilized for interrupting DC current with injection of high-frequency inverse current from a commutating capacitor precharged to HVDC line voltage. Also, the effectiveness of application of the HVDC breaker to an HVDC system with two parallel transmission lines is demonstrated through the EMTP simulation.

Surface treatment of aluminum alloy at room temperature with titanium-nitride films by dynamic mixing

Titanium-nitride coating films were prepared on aluminum alloy plates at room temperature with simultaneous ion implantation and metal vapor deposition (dynamic mixing) by using a high current ion source. The films were analysed by means of Auger electron spectroscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The results showed the presence of small amount of oxygen and carbon impurities due to a high current density (0.5–1.0 mA/cm2) of the nitrogen beam (energy: 20 keV). Films of 1.2 μm thickness showed uniform composition. Titanium-nitride coated aluminum alloy (film thickness: 15 μm) was ten times harder than the untreated one. The coated plate was examined by a pin-on-disc wear tester. The results showed better wear properties.

Development and Field Application of Metallic Return Protecting Breaker for HVDC Transmission

This paper describes the system requirements, circuit and component selections, development and field tests on a metallic return protecting breaker for an HVDC transmission system. Self oscillation phenomenon, generated in the course of DC current interruption by an air blast circuit breaker, is utilized to force the current to zero. Also discussed is outlook for development of an HVDC main line circuit breaker.

Development of large scale ion beam milling machines

Abstract The higher-speed implementation and higher integration of electronic equipment gives increasingly higher importance to high-accuracy super-fine machining technology. A developed ion beam milling machine, which responds to this requirement, is a useful means to implement the higher performance of electronic equipment. The machine compactly comprises a large scale ion source that has been developed by the application of the essence of neutral beam injection equipment for heating plasma in nuclear fusion facilities, and a water cooled substrate holder that is capable of simultaneously treating up to 16 substrates and is rotated and revolved at any gradient angle with respect to the beam. The large scale ion source is used to generate uniform beams at low divergence angles. The result is that high accuracy and the highest throughput unheard of can be achieved with machining deviations at ± 3% or less.

Development of a high deposition rate machine by ion beam sputtering

Abstract Recently a deposition method by ion beam sputtering was developed which is interesting for making films with superconductive, optical or magnetic properties. The ion beam sputtering method has many advantages such as process controllability, low working pressure and no plasma contact. However, the deposition rates have not been so high as those of other methods such as magnetron sputtering. The authors have developed a large-capacity and high-efficiency ion source by applying the nuclear fusion ion source technology, and realized a high deposition rate ion beam sputter machine by using this ion source. This machine has a high-speed semiconductor switch for quick interruption and restart. It also maintains a constant deposition rate by controlling the ion beam current according to the rate monitor signal. A deposition rate of 340 nm/min is obtained for a copper film at a substrate 250 mm distant from a target, which is nearly the same level as with magnetron sputtering.