The oldest area of plasma physics known as "electric discharges in gases" developed for many years mainly as an empirical and phenomenological science.
Alfven noted sarcastically that "most of theoretical physicists considered this area of science in a haughty marvner because it appeared to be extremely complex and intricate. Striations, double layers, and a great number of oscillations and instabilities were being observed. The electron temperature frequently happened to be up to the order of the value or two higher than the temperature of the background neutral gas, and the value of the ion temperature was confined to the range between electron and gas temperatures. In short, this was the area of physics where it was inconvenient to apply mathematically elegant theories".


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