Electron density fluctuation in a dusty plasma

The expressions of electron density fluctuation produced by dust particles in a dusty plasma are derived. It is shown that the fluctuation comes from three different sources. The first source is the thermal motion of the dust particles, which is of a fluctuation power spectrum proportional to n(d)Z(2). The second source is the charge change of the dust particles, which is of a power spectrum proportional to n(d)(2)Z(3). The third source is the eigenmode oscillation of the dust particles, which is of fluctuation power spectrum proportional to rootn(d). The powerful electron density fluctuation exists in a dusty plasma due to the fact that the dust particles are highly charged. The results may explain the strong electromagnetic scattering by a space dust layer in the Earth's mesosphere.