Laser-based three-dimensional dust trajectory diagnostic

Time-resolved, in-situ and non-intrusive dust diagnostics is required in many plasma applications, not only in processing plasmas but also in tokamak plasmas, and laser-based diagnostics is regarded as one of the most promising solutions for this purpose. Also, the three-dimensional dust diagnostics has been spotlighted because it can provide higher dimensional information related to the dust motion than one- or two-dimensional diagnostics. A high-sensitivity three-dimensional laser-based diagnostic system is developed in this work to determine the trajectory of dust by adopting the multi-laser-sheet method with two charge-coupled-device cameras. Using this diagnostic system, the trajectories of dust immersed in plasma were investigated in three dimensions under various gas pressures and the damping effect of the neutral gas was observed.