Study on a new type of square superlattice pattern in dielectric barrier discharge

The new type of square superlattice pattern that big and small spots are not completely inserted into the center of each other is firstly observed in the mixed gas discharge with high argon content. Its spatial-temporal dynamics investigated by an intensified charge coupled device camera (ICCD) and photomultiplier (PMT) show that it is an interleaving of three different sub-lattices, and the discharge sequence of substructures in each half voltage cycle is: small spots, halos and central spots. In addition, the discharge current of central spots is corresponding to two distinct pulses at the negative edge of the each half voltage cycle, which indicates that discharge time is selective. The intensity of electric field is non-uniform around different central spots due to the selective discharge of central spots and different quantities of wall charges of the halo being consumed. Therefore, each small spot is not completely inserted into the center of four big spots during discharging.