Initial experiments in the Idaho Dusty Plasma Device

The Idaho Dusty Plasma Laboratory has recently begun operation. Work to date has used an argon dc glow plasma in which dust particles are levitated. Langmuir probe measurements indicate plasma densities in the range 1014-1015 m-3 and electron temperatures in the range 1-5 eV depending on plasma conditions and spatial location. To date monodispersive particles with a diameter range of 20-30 μm have been used. The observed dust clouds have dust densities in the range 1010-1012 m-3. Dust particle average kinetic energies are typically near the electron temperature in magnitude. The bulk of the dust cloud is in a crystalline solid configuration. The motion of the dust can best be characterized as collective normal mode activity. Spectra of the particle motion reveal the distinction between collective and random motion. The dust charge has been measured to be on order of -104e. The variations of particle energy and charge within the dust cloud have been measured