CHARGE-DENSITY FLUCTUATION OF LOW-FREQUENCY IN A DUSTY PLASMA

The charge density fluctuation of low frequency in a dusty plasma, whi ch is derived from the longitudinal dielectric permittivity of the dus ty plasma, has been studied by kinetic theory. The results show that t he P value, which describes the relative charge density on the dust in the plasma, and the charging frequency of a dust particle Omega(c), w hich describes the ratio of charge changing of the dust particles, det ermine the character of the charge density fluctuation of low frequenc y. For a dusty plasma of P<<1 when the charging frequency Omega(c) ism uch smaller than the dusty plasma frequency omega(d), there is a stron g charge density fluctuation which is of character of dust acoustic ei genwave. For a dusty plasma of P>>1, when the infrequency Omega(c) is much larger than omega(d) there are weaker fluctuations with a wide sp ectrum. The results have been applied to the ionosphere and the range of radius and density of dust particles is found, where a strong charg e density fluctuation of low frequency should exist.