Vertically elongated three-dimensional Yukawa clusters in dusty plasmas

Yukawa clusters in dusty plasmas have been investigated experimentally with respect to their structural properties when they become elongated. These elongated clusters can be formed by creating an anisotropic confinement potential with changing plasma power. It is observed that increasing deformation of the cluster is accompanied by a vertical alignment of the particles although the alignment is neither seen nor expected for spherical clusters. Simulations of elongated clusters with and without the action of an ion focus have been performed and compared to the experiment. It has been revealed that the structure of spherical clusters is unaffected by the presence of a weak ion focus whereas elongated clusters visibly react to the presence of a weak ion focus.