Collision Between Two Spots in a Hexagonal Superlattice Pattern in Dielectric Barrier Discharge

The collision between two spots in a hexagonal superlattice pattern in a dielectric barrier discharge is studied by a fast intensified camera. The hexagonal superlattice pattern is composed of small and big spots. In the amplified pictures, each big spot appears as four small spots at long exposure time, while it presents a pair of spots at short exposure time. A series of images, which arc taken by a fast intensified camera, displays that two spots collide continually and the orientation of two spots changes about 90° after each collision. The superposition of a lot of collisions between two spots appears as four small spots.