抄録
The theory of strongly coupled charged systems is briefly described. Emphasis is placed on thermodynamic properties and possible thermodynamic instability and its observation. When one looks at the subsystem composed of particles of one species and regards other particles in the charge-neutral system as background, the compressibility of the subsystem diverges at not-so-strong coupling and critical phenomena related to this thermodynamic instability are expected. In reality, however, the background gives larger contribution to the pressure and masks the critical behavior. In the case of dust particles in dusty plasmas, there is a possibility that the contribution of the background can be overcome and these phenomena can be directly observed for the first time. This is due partly to the large number of charges on macroscopic dust particles. At the same time, the large mass of dust particles are not free from the influence of gravity and the microgravity emvironment is necessary in investigation of critical phenomena in dusty plasmas.
