ABSTRACT
This entry describes the phenomenon of microwave-generated fireballs ejected from molten hot spots, mainly in solids, to the air atmosphere. This generic concept of plasmoid ejection by localized microwaves has been demonstrated in various substrate materials, e.g., silicon, copper, glass, germanium, titanium, basalt, and salty water. The various experimental schemes and results obtained therefrom are described here in a unified approach. The presence of nano- and microparticles observed in these fireballs by small-angle X-ray scattering and by scanning electron microscope relates these fireballs to dusty (complex) plasmas. These laboratory-made fireballs also seem to resemble the natural, rarely observed, ball-lightning phenomena. Their further studies may lead to practical applications as well, such as combustion techniques, nano-powder production, energy conversion, coating, and material identification. Both scientific and applicative aspects of these microwave-generated fireballs are reviewed in this entry.
