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P: Plasmaphysik

P 17: Staubige Plasmen 1

P 17.3: Vortrag

Montag, 7. März 2005, 11:45–12:00, HU 3059

Three dimensional plasma crystals in microgravity — •Peter Huber¹, Vladimir E. Fortov², Alexei V. Ivlev¹, Andrey M. Lipaev², Vladimir I. Molotkov², Gregor E. Morfill¹, Milenko Rubin-Zuzic¹, and Hubertus M. Thomas¹ — ¹Max Planck Institute for extraterrestrial Physics, — ²Institute for High Energy Densities, 127412 Moscow, Russia

In many crystallisation experiments with PKE-Nefedov, we observed crystalline order in a small area close to the sheath region. Even after several minutes the size of the crystal did not increase. In one of the latest experiments, a few minutes after injecting particles, when the complex plasma has reached a steady state, the pressure was reduced in little steps. Every step causes a little ’puff’ of gas, which disturbs the equilibrium position of the particles. These little kicks precipitate an annealing of crystal defects, so that a large crystalline region is formed. A scan in depth provided us finally with a 3-dimensional view of the crystal. In contrast to crystals with similar particles under normal gravity it was found that in space the crystal planes where not mainly oriented parallel to the electrode. It is found that the crystal consists of domains with different orientation and different crystalline structure. This allows us to investigate the physics of 3-D domain boundaries, de-excitation of lattices, annealing etc. at the kinetic (individual particle) level.