Analyzing phase separation processes in binary dusty plasmas using a polarization-sensitive camera

Abstract

Under the weightlessness conditions of parabolic flights, phase separation processes in a binary mixture of dust particles in a dusty plasma have been experimentally studied using a polarization-sensitive camera. The camera allows a pixel-wise derivation of the polarization state of the light scattered by the dust. With this, the light scattered from individual particles in a dust cloud consisting of dust particles with two different sizes has been analyzed. By comparison with analytical calculations of the scattered light polarizations, a technique has been developed to discriminate between the two different species, even for small size disparities. With that, the dynamics of the phase separation process of the two species is followed over the entire parabola and it is found that the larger particles preferably assemble on the outer parts of the dust cloud whereas the smaller particles accumulate on the inner parts.