Apparent surface tension in complex (dusty) plasmas

Summary form only given. Complex (dusty) plasmas consist of microparticles embedded in a plasma. The microparticles acquire charges of several thousands of electrons and interact with each other. As the microparticles are usually all charged negatively, they repell each other, and no attractive forces are expected. Here, we report on experiments in which an apparent surface tension was observed that compressed the boundary of the microparticle cloud and led to the formation of roughly spherical microparticle ensembles.