Torsion density related to electrode and crystal size

Abstract

Complex plasma systems form monolayer dust crystal structures by balancing electric and gravitational forces to precisely levitate particles of the same size and mass. Ion wake fields are the source of nonreciprocal vertical force interactions which can form torsions in such a system. Torsions are a non-Hamiltonian feature, consisting of two dust particles which vertically leave the plane of the crystal and begin to oscillate horizontally within a force cage formed by the remaining lattice of the crystal. Torsions provide an excellent means for studying the energy transfer mechanism of ion wakefields. Many questions remain about what effects lead to the development of torsions and whether there is a pattern to torsion placement within the crystal. An important next step is to determine whether the presence of a single torsion increases or decreases the ease of subsequent torsion formation nearby in the lattice. Employing a modified GEC rf reference cell with a much larger electrode than previously studied we have formed torsions using various sizes of electrodes and dust crystals. In this talk we will explore the data collected from this system to answer this question.