Summary and Outlook

Part of the Springer Theses book series (Springer Theses)


The work described in this thesis was concerned with the experimental investigation of the phase state of two-dimensional complex plasmas, consisting of micrometer sized plastic spheres immersed in an Argon plasma. Error Analysis The data analysis was performed on recorded images containing the illuminated particles. Particle coordinates were extracted directly from this images by a tracking algorithm, which provides the possibility to observe physical processes on a fundamental kinetic level. The estimation of uncertainties due to the particle tracking procedure and due to pixel-noise in the recorded images was an important part of this work. Artificial images have been generated, containing particles as accumulations of “illuminated” pixels, and a random particle motion has been simulated in series of consecutive images. The influence of different quantities of pixel-noise and particle–image sizes (corresponding to the number of illuminated pixels per particle) was investigated. The procedure yielded estimates for the uncertainties which could be transferred to the experimental data, and enabled to identify the limits of resolvable distances. This allowed the validation especially of the measurement of particle velocities and displacements above the error threshold. The uncertainties were considered throughout the data analysis for all experiments individually. Only by considering this errors, the scientific interpretation of the acquired data gains a physical meaning.


Recorded Image Orientational Order Defect Fraction Plastic Sphere Scientific Interpretation 
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    J. Frenkel, Kinetic Theory of Liquids (Dover Publications, New York, 1955)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg  2011

Authors and Affiliations

  1. 1.Max Planck Institute for Extraterrestrial PhysicsGarchingGermany

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