抄録
Dust particles of micro-meter size are levitated around a sheath in discharges. Gravity pushes the dust particles from a bulk of plasma to the sheath on the ground. Microgravity conditions brought by sounding rockets, parabolic flights of aircract and the International Space Station allow the dust particles to suspend in the bulk of plasma. Many researches have required phenomena of the dust particles under microgravity to be understood with connected to plasma parameters. Here several examples estimating the plasma parameters of microgravity experiments were shown, and described as manners to elucidate the phenomena in dusty plasmas with the plasma parameters. A rough estimation of ion density was obtained in observing wave propagation, and spatial distribution of the dust particles changed by a discharge control was understood in measuring electron density.
