Close-up of the central electrode of a plasma globe, showing streams of glowing plasma around it. A plasma globe is a glass sphere filled with noble gases (usually neon, krypton and xenon) at low pressure, with a very high voltage, high frequency electrode at its centre. The electrical energy ionises regions of the gas, which form a glowing plasma that extends to the insulating glass shell of the globe. The streams of plasma are attracted to conducting objects placed on the outside of the globe, such as fingers. |