Dusty plasmas are ionized gases that contain microscopic charge carriers – often simply referred to as dust, representing a large variety of possibilities, including ice particles, water drops, or simply dust. Interplanetary space, comets, planetary rings, asteroids, the moon, and aerosols in the atmosphere are all examples where electrons, ions, and dust particles coexist. This emerging field bridges plasma physics studies with celestial and granular materials mechanics.
Scientists are interested in dusty plasmas for a variety of reasons:
- Dust particles immersed in plasmas and bathed in UV radiation collect electrostatic charges and respond to electromagnetic forces, in addition to gravity.
- Dust particles in plasmas are unusual charge carriers: they are heavier and can have larger negative or positive time-dependent charges, introducing new temporal and physical characteristic scales.
- Dust particles can communicate non-electromagnetic effects, such as gravity, drag, and radiation pressure to the plasma—acting as free energy sources. Dust can influence the collective plasma behavior, altering the traditional plasma wave modes and triggering new types of waves and instabilities.
- LASP, the Departments of Physics, and the Department of Aerospace Engineering have a rapidly growing program in dusty plasma theory, laboratory investigations, rocket experiments, and spacecraft instrumentation. We recently established the Colorado Center for Lunar Dust and Atmospheric Studies, which is a member of the NASA Lunar Science Institute, to study dusty plasma phenomena on the lunar surface.