So what is the plasma in those TV’s? I assumed it was a gas, but what comprises it? Also, is it really “plasma” by definition or is the term more of a marketing term?
It is more like a minature fluorescent lamp. There is some plasma formed (ionised gas) caused by the ejection of electrons into the gas, which causes an ultraviolet glow, which stimulates the coloured phosphors.
see http://www.howstuffworks.com/plasma-display1.htm
Yes, they definitely have plasma in them when they’re operating. It’s not plasma when you buy it, only when they turn on. Like the steam in a steam cleaner. When it’s off, there is a little gas instead, probably at a pressure less than atmospheric (because lower pressure lets it become a plasma with less power).
Don’t know what gas or gas mixture they use.