Monte Carlo simulation based on test particle representation is carried out in order to investigate the strike point pattern of ions on the Local Island Divertor (LID) head in the Large Helical Device configuration. The pattern on the LID head is numerically observed by tracing the guiding center orbits of the test particles under the effects of the Coulomb collision, and the observations show that the pattern depends strongly on the collisionality.

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In order to clarify the electromagnetic acceleration mechanisms of an applied-field magneto-plasma-dynamic arcjet (MPDA), magnetic fields are measured in detail near the MPDA outlet. Plasma current density is calculated using the Maxwell equation (rotB=μ₀j), and then spatial distributions of Lorentz forces (j×B forces) are evaluated. A uniform external magnetic field is deformed by a strong diamagnetic effect near the MPDA outlet, and as a consequence, a converging magnetic nozzle configuration is formed. It is found that an axial Lorentz force F_z (=j_rB_θ-j_θB_r) is almost eliminated by the deceleration force (the j_θB_r force), which results from the diamagnetic effect. The deceleration force can be converted to the acceleration one in an externally-applied diverging magnetic field.

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A series of experimental programs on the JAERI Fusion Torus-2M (JFT-2M) was completed in March, 2004. In the two decades of experimental operation since the first plasma on April 27, 1983, many significant results leading the fusion energy research and plasma physics have been produced in researches on high confinement mode (H-mode), heating and current drive, advanced plasma control, compatibility of low activation ferritic steel with improved confinement mode, etc. Among these results, some selected important results are presented.

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Lightning has caused lot of damages to not only human beings, but structures, power transmission and distribution systems and transportation systems. Furthermore, recent information-oriented society becomes more vulnerable to lightning than that of old days. To understand lightning, several kinds of lightning observations have been carried out and novel observation equipments using opt-electronics technology have been developed. Based on the observations and theoretical analysis, lightning protection design has been established. In this article, lightning hazards, lightning observation techniques and lightning protection design are reviewed. Problems for future studies are also demonstrated.

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Four scientific demonstrative presentations concerning a lightning are presented in this article. All presentations can be easily performed on the scientific events held in educational and/or research institutions, such as university, college, research center, elementary, secondary and high schools. The first topic is long gap discharge which shows the model of the lightning from lightning clouds to ground. The high voltage is generated using an impulse voltage generator, which consists five capacitors, gap switches, and dc high-voltage power supply. Human shaped wet sponges were employed in the presentation as a human-body. The second topic is turning-on a fluorescent lamp without direct power supply using Tesla coil as electromagnetic wave radiation source. We show not only some commercial products of Tesla coil but also show how to construct the Tesla coil with much higher output voltage than the merchandise. The third demonstration is a ball lightning using a microwave. Finally, we show a handicraft of small lightning generation on the name card using a piezoelectric crystal in an electric throwaway lighter.

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