| 摘要 |
PROBLEM TO BE SOLVED: To improve the heating efficiency and to obtain hyperfine particles with high purity at a high producing rate by instantaneously flowing a large current through a metallic member with a fine-wired shape small in a crosssectional area, heating the metallic member, melting and vaporizing the metallic member to form into a plasma state and thereafter executing cooling and solidifying. SOLUTION: A large current composed of a pulse current or the like is instantaneously made to flow through a fine wire of metal small in a cross-sectional area and is heated. By this heating, the metallic fine wire is melted and vaporized to form into a plasma state. The metallic member in a plasma state is expanded and diffused in a gas and is rapidly cooled. At this time, by cooling it in a uniform way spatially, many solid particles are solidified to grow in the gas. Next, when cooling is executed to a certain temp. or below, the growth of the solid particles stops, and the particle size thereof is regulated to final one. This particle size can be controlled by gas pressure. Successively, the formed solid particles are recovered to obtain hyperfine particles. Since the metallic member has a fine-wired shape, the metallic member can swiftly be vaporized.
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