Tau.Neutrino said:
Stable plasma ring created in open air for the first time
Plasma is one of the more mysterious phases of matter, only existing on Earth fleetingly in the form of lightning or contained inside neon signs. Now a team of engineers from Caltech has created a stable ring of plasma in open air, using just a high-pressure jet of water and a crystal plate. The technique could, in the long run, unlock the potential for plasma to be used for storing energy.
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“That jet of water is extremely narrow and highly pressurized, measuring just 85 microns wide and with a force of 9,000 psi, which strikes the plate with an impact velocity of about 1,000 ft per second (305 m per second). To illustrate those numbers, the team likens the jet to a human hair moving at the speed of a bullet.
“The crystal surface is negatively charged, and when the water hits it and flows outwards, it carries with it positively-charged ions. That builds up a static (or triboelectric) charge, which causes electrons to flow up to the surface of the water and ionize the atoms and molecules in the air above it. That creates a ring of plasma in the air, which will stay steady as long as the stream of water is flowing.”
I like it, wish I’d thought of it.
But on the other hand it’s not too different to a cathode ray tube.