High Quality Content by WIKIPEDIA articles! A plasmoid is a coherent structure of plasma and magnetic fields. Plasmoids have been proposed to explain natural phenomena such as ball lightning, magnetic bubbles in the magnetosphere, and objects in cometary tails, in the solar wind, in the solar atmosphere, and in the heliospheric current sheet. Plasmoids produced in the laboratory include Field-Reversed Configurations, Spheromaks, and the dense plasma focus. The word plasmoid was coined in 1956 by Winston H. Bostick (1916-1991) to mean a "plasma-magnetic entity". The plasma is emitted not as an amorphous blob, but in the form of a torus. We shall take the liberty of calling this toroidal structure a plasmoid, a word which means plasma-magnetic entity. The word plasmoid will be employed as a generic term for all plasma-magnetic entities.