Plasmas are collections of charged particles that can exhibit an impressively diverse set of collective phenomena. They exist in an extraordinary variety of environments and span a great range of densities and temperatures, from 15 million kelvin in the core of the Sun to 200 K in the ionosphere and from 1030 particles per cubic centimeter in a white dwarf to 1 particle per cm3 in interstellar space. They can find application in lighting sources, manufacturing of computer chips, and fusion energy research. Plasmas created in the laboratory are used to replicate and study those that occur naturally and to probe the fundamental and complex behavior of plasmas.
Plasmas tend to be hot, because collisional energies of 1 eV or higher are required to ionize atoms and molecules. But in the past decade, a new laboratory plasma has emerged on the scene—the ultracold neutral plasma. With electron and...
