PROBE-INDUCED PARTICLE CIRCULATION IN A PLASMA CRYSTAL

A biased probe placed in an argon plasma near the sheath edge has been found to alter significantly the structure and properties of a plasma crystal, inducing particle circulation around a stable crystalline is land. The origin of the island and the circulation an attributed to th e formation of a nonuniform electric field in the crystal region by th e probe. Variation in the space-charge flux due to the ion wake associ ated with the probe is also considered important, as it may alter the grain charge and the transfer of momentum to the dust particles.