Microparticles deep in the plasma sheath: Coulomb explosion

A cloud of microparticles was trapped deep in the sheath of a radio-frequency (rf) discharge, very close to the lower (grounded) electrode of the plasma chamber. This was achieved by employing a specifically designed rf-driven segment integrated in the lower electrode, which provided an additional confinement compressing the cloud to a very high density. After switching the rf-driven segment off, the cloud exploded due to mutual interparticle repulsion. By combining a simple theoretical model with different numerical simulation methods, some basic properties of complex plasmas in this highly non-equilibrium regime were determined. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4754007]