Torsion Phase Synchronization in Complex Plasma Crystals*

Complex plasma consists of micron sized dust particles levitating in a weakly ionized gas. Given strong enough interparticle interactions between the dust particles, a plasma crystal can be formed. Torsions are an anomlaous occurence in monolayer plasma crystals where dust particles pair up and orbit outside the plane of the crystal. Their initial obeservation led to two formation mechanism possibilities, ion-wake induced mode coupling and ion drag caused by local rotations in the ion flow. As such, measuring the forces on the particles adjacent to a Torsion provide a direct look into the shape of the ion wake field. At Baylor University, a GEC RF Reference Cell is being used to experimentally study the interaction between Torsions and the surrounding particles in a monolayer lattice structure to ascertain whether multiple Torsions have the same frequency for identical phase angles with each cycle. This paper considers both the formation and the effects of Torsions on the surrounding particles experimentally, employing high speed cameras and particle tracking software. The results are then compared to previous results, with extrapolated outcomes mapped to the ion wake fields and phase angles of each individual Torsion.