Plasmoid
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, solar atmosphere, and in the heliospheric current sheet. Plasmoids produced in the laboratory include the compact toroids field-reversed configurations, spheromaks, and filamentary variants in plasma focus">Plasma (physics)">plasma focuses.
The word plasmoid was coined in 1956 by Winston H. Bostick to mean a "plasma-magnetic entity":
Characteristics
Bostick researched the basic traits, and many details, of plasmoids.A plasmoid has an internal pressure stemming from both the gas pressure of the plasma and the magnetic pressure of the field. To maintain an approximately static plasmoid radius, this pressure must be balanced by an external confining pressure. In a field-free vacuum, a plasmoid expands and dissipates rapidly.
Plasmoids have been formed in discharges with local magnetic field strengths on the order of 16,000 tesla.