First experiments in the Dusty Plasma Experiment device

The Dusty Plasma Experiment (DPX) is a new experimental plasma device at Fisk University. DPX is constructed from two, 4 in. diam ISO 100 stainless steel six-way crosses. Initial experiments have successfully produced argon dc glow discharge plasmas. Measurements of the plasma parameters using Langmuir probes, in the absence of the dust particles, give plasma densities n∼1015 m−3 and electron temperatures ranging from Te=2 to 5 eV. Dusty plasmas are made by suspending 40 μm diam silica (SiO2) particles in the argon plasma. Dust clouds in the DPX device have densities nd∼109–1010 m−3. This paper describes the hardware and initial operation of the DPX device. Measurements of the three dimensional spatial structure of dust clouds are discussed. Dust acoustic modes with frequencies in the range f=10–20 Hz in the dust clouds are also identified. Particle image velocimetry techniques are used to characterize the spatial distribution and the temporal evolution of the velocities of the dust particles in the plasma.