Search

Your search keyword '"Menzel, K."' showing total 5 results
Start Over Author "Menzel, K." Topic reduced gravity environments
5 results on '"Menzel, K."'

1. Nonlinear Phenomena and Self-Organization in Dusty Plasmas.

Author

Arp, O., Menzel, K. O., Caliebe, D., Bockwoldt, T., and Piel, A.

Subjects
*DUSTY plasmas, *MOLECULAR dynamics, *PLASMA waves, *PLASMA density, *NONLINEAR oscillators, *THEORY of wave motion, *REDUCED gravity environments
Abstract

Experiments with extended three-dimensional dusty plasmas under microgravity conditions were performed to study the complex wave pattern of self-excited dust-density waves and its interaction with the plasma. The simultaneous observation of the dust-density fluctuations and the plasma glow revealed that the observed wave phenomenon affects the plasma in the complete discharge. In particular, our investigations suggest, that self-excited dust-density waves are the product of a self-organized system consisting of the dust cloud, the plasma, and the external circuit. The complex wave pattern is a consequence of partial synchronization of neighboring regions inside the dust cloud and can be modeled by a system of coupled nonlinear oscillators. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

2. 3D Particle Dynamics in Dusty Plasmas under Microgravity.

Author

Buttenschön, B., Himpel, M., Melzer, A., Caliebe, D., Menzel, K. O., Arp, O., and Piel, A.

Subjects
DUSTY plasmas, REDUCED gravity environments, PLASMA gases, PLASMA dynamics, STEREOSCOPIC cameras, TRAJECTORIES (Mechanics)
Abstract

The dynamical properties of individual particles in a dusty plasma under microgravity conditions are investigated by means of a stereoscopic camera setup. This camera system allows the three-dimensional reconstruction of particle trajectories in a volume of approximately (15×15×15) mm3 in three dimensions. We present measurements in two different regions of a dust cloud on parabolic flights. First, the force field in the void is reconstructed from probe particles in three dimensions. Second, the oscillation of particles at the outer dust cloud surface is evaluated, and the relation to dust-density waves in the dust cloud is investigated. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

3. Chain of coupled van der Pol oscillators as model system for density waves in dusty plasmas.

Author

Menzel, K. O., Arp, O., and Piel, A.

Subjects
*VAN der Pol oscillators (Physics), *DUSTY plasmas, *DENSITY wave theory, *NUMERICAL analysis, *REDUCED gravity environments
Abstract

Recent investigations of dust-density waves in a dusty plasma under microgravity conditions [ K. O. Menzel et al. Phys. Rev. Lett. 104 235002 (2010)] showed that the wave field consists of distinct regions of different frequencies. These so-called frequency clusters are known from simulations of chains of mutually coupled van der Pol oscillators. The behavior of distinct oscillators adjacent to the cluster boundaries were studied numerically. The interaction of these oscillators leads to periodic frequency pulling, a typical feature of driven van der Pol oscillators that is also observed in our experiments. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

4. Frequency clusters and defect structures in nonlinear dust-density waves under microgravity conditions.

Author

Menzel, K. O., Arp, O., and Piel, A.

Subjects
*RADIO frequency, *REDUCED gravity environments, *BIFURCATION theory, *CLUSTER theory (Nuclear physics), *DISTRIBUTION (Probability theory)
Abstract

Density waves in a dusty plasma emerge spontaneously at low gas pressures and high dust densities. These acousticlike wave modes were studied in a radio-frequency discharge under microgravity conditions. The complex three-dimensional wave pattern shows a spatially varying wavelength that leads to bifurcations, i.e., topological defects, where wave fronts split or merge. The calculation of instantaneous wave attributes from the spatiotemporal evolution of the dust density allows a precise analysis of those structures. Investigations of the spatial frequency distribution inside the wave field revealed that the wave frequency decreases from the bulk to the edge of the cloud in terms of frequency jumps. Between those jumps, regions of almost constant frequency appear. The formation of frequency clusters is strongly correlated with defects that occur exclusively at the cluster boundaries. It is shown that the nonlinearity of the waves has a significant influence on the topology of the wave pattern. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

5. The Structure of Nonlinear Dust-Density Waves under Microgravity Conditions.

Author

Menzel, K. O., Arp, O., and Piel, A.

Subjects
*PLASMA dynamics, *DUSTY plasmas, *PLASMA waves, *REDUCED gravity environments, *PLASMA density, *PROPERTIES of matter, *TOPOLOGICAL spaces, *ELECTRIC oscillators
Abstract

A chain of mutually coupled nonlinear and self-sustained oscillators is studied numerically. The simple model allows to explain the topological structure of self-excited dust-density waves under microgravity conditions. The basic properties of the model are presented and compared with experimental studies. [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results