Molecular dynamics simulations were performed to estimate the composition of deposited products from alumina ablation plume at the atomic level. The parameters considered were the Al/O ratio of ablation plume and the temperatures of ablation plume and recovery plate surface. Simulation results showed that oxygen-deficient alumina was formed on the recovery plate surface, whose Al/O ratio was in good agreement with the composition of oxygen-deficient alumina obtained in the experiment. The simulation results also showed that the Al/O ratio of the deposited layer could be increased when the Al/O ratio of the alumina ablation plume was larger and the temperature of the recovery plate surface was higher. These results suggest that the Al/O ratio can be increased by repeated process of laser ablation and deposition of ablation plume, and the relationship between the Al/O ratio and the number of repetitions of this process was modeled and evaluated.

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Characteristics of the inductively coupled nitrogen plasma driven by high voltage burst pulses with 150 kHz-band were investigated. The results showed that the coil current of 64 A flowed into the solenoid coil at 300 V applied voltage, which was consistent with 83 Ω of equivalent load impedance before the plasma ignition. The coil voltage and current decreased to 2.7 kV and 45 A, respectively, with plasma ignition. The electron temperature and the ion density were obtained as 3.0 eV and 4.1×1019 m-3, respectively, at the position of 45 mm by a double probe method. The ion density increased with increasing input power. On the other hand, the electron temperature was almost independent of the input power. The electron temperature slightly decreased with increasing the gas pressure. The ion density was almost independent of the gas pressure. The electron temperature and the ion density decreased with increasing distance from position of the coil center. The emission intensity of the nitrogen second positive system (SPS; 337.1 nm) and first negative system (FNS; 391.4 nm) increased with increasing input power. The ratio of FNS/SPS increased with increasing input power.

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Magneto-Plasma-Dynamic (MPD) thrusters have been investigated in Osaka Sangyo University. The purpose of this study is to develop a practical MPD thruster system for future transportation among planets and satellites in the Solar System, specially for manned Mars exploration as one of the In-Space Transportation & Propulsion project in collaboration with the Japan Aerospace eXploration Agency (JAXA). A magnetic field is applied to an MPD thruster by using permanent magnets of samarium cobalt (SmCo) magnets. In this study, performance characteristics were measured using special gases of carbon dioxide, methane and ammonia as original materials in planets and satellites in the Solar System; that is, propellant can be supplied just on the planets and satellites of Moon, Mars and Jupiter Moons; argon and nitrogen also used in basic experiments. Because operations with carbon dioxide and methane were very unstable compared with cases with other gases, the structure and operational condition should be examined to design a thruster suitable for transportation in the Solar System. On the other hand, a high performance with 5 mg/s of NH3 at 1.0 kW was a thrust of 60 mN, a specific impulse of 1,500 s and a thrust efficiency of 30.0% with an axial magnetic field strength of 0.157 T.

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Electric power generation technologies using renewable energies such as wind power generation and solar power generation have been introduced recently as solution for oil prices rise and global warming. Among them, we pay attention to the study of correlation with dye sensitized solar cells (DSSC). When manufacturing the DSSC, the transparency of the substrate is required so that the titanium dioxide dispersion system is baked onto the substrate without using silicon. This study explores TiO2 film thermal spraying techniques on transparent acrylic substrates. Through this experiment, we have obtained the temperature conditions, current conditions and distance conditions required to form a TiO2 film on a transparent resin substrate. In this experiment, a TiO2 film with an anatase-type structure was obtained.

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