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Filamentary structures in low-pressure, low-temperature plasmas are produced when strong magnetic fields are applied parallel to the electric field defined by parallel electrodes. Filamentary structures are regions within the plasma that have distinct properties such as optical brightness and extend along the magnetic field lines. In our experiments, an argon, radio frequency discharge is exposed to a strong background magnetic field in the magnetized dusty plasma experiment at Auburn University. Different forms of filamentary structures emerge in the plasma such as columns, target, or spiral-like structures. To investigate the origin and the characteristics of these patterns, we have developed a three-dimensional fluid model that can reproduce the experimental observations which enables us to investigate the underlying mechanisms of the filamentation process.

In this paper, the formation of imposed patterns due to placing a wide wire mesh ('waffle' electrode) in the bulk of a strongly magnetized (B 1 T) plasma is investigated both experimentally and numerically. A new double head electrostatic probe was designed for the experiments that allows for measurements of the floating potential beneath the mesh in the magnetized plasma. The measurements using this probe revealed that due to the presence of the 'waffle' electrode in the bulk of the magnetized plasma, an organized pattern appears in the plasma potential. As a result of this imposed pattern, when dust particles were added to the experiments, they became trapped beneath the edges of the 'waffle' electrode. The effects of placing a wire mesh in the bulk of a magnetized plasma were further investigated using fluid and particle-in-cell (PIC) simulations. These simulations were able to qualitatively reproduce the experimental observations. The results of the simulations showed that the imposed patterns arise due to differences in the cross-field transport of the electrons and ions in the presence of magnetic field.

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