2013/05/24 by Shinya Iwashita, E Schüngel, Edmund Schüngel +8
Physics and Astronomy · #Asymmetry #Atomic physics #Cold Atom Physics and Bose-Einstein Condensates #Computational physics #Debye sheath #Dust and Plasma Wave Phenomena #Electric field #Harmonics #Ionosphere and magnetosphere dynamics #Levitation #Materials science #Mechanics #Micrometer #Optics #Phase (matter) #Physics #Plasma #Symmetry (geometry) #Voltage #physics.plasm-ph
paper · pdf · doi:10.1088/0022-3727/46/24/245202
25 pages, 16 figures
arxiv created 2013/05/24 · openalex publication_date 2013/06/03 · arxiv updated 2015/06/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
The control of the spatial distribution of micrometre-sized dust particles in capacitively coupled radio frequency discharges is relevant for research and applications. Typically, dust particles in plasmas form a layer located at the sheath edge adjacent to the bottom electrode. Here, a method of manipulating this distribution by the application of a specific excitation waveform, i.e. two consecutive harmonics, is discussed. Tuning the phase angle θ between the two harmonics allows one to adjust the discharge symmetry via the electrical asymmetry effect (EAE). An adiabatic (continuous) phase shift leaves the dust particles at an equilibrium position close to the lower sheath edge. Their levitation can be correlated with the electric field profile. By applying an abrupt phase shift the dust particles are transported between both sheaths through the plasma bulk and partially reside at an equilibrium position close to the upper sheath edge. Hence, the potential profile in the bulk region is probed by the dust particles providing indirect information on plasma properties. The respective motion is understood by an analytical model, showing both the limitations and possible ways of optimizing this sheath-to-sheath transport. A classification of the transport depending on the change in the dc self-bias is provided, and the pressure dependence is discussed.