Plasma Technology

What is low-pressure plasma?

The gentle power of the fourth aggregate state

Matter changes its form of appearance at specific temperatures. Generally, solid, liquid and gaseous aggregate states are known. However, there is another state – the plasma. Plasma is the ionized form of a gas and is also named “fourth aggregate state”. The difference between neutral gas and plasma is the significantly higher electrical conductivity and chemical reactivity.

Samples for naturally occurring plasmas are lightning, northern lights or sun. However, in our everyday lives we also encounter plasma in the form of fluorescent lamps, low-energy lamps or television.

Artificially produced plasmas are e.g. the plasma lamp and the electric arc in welding technology.

Low-pressure plasma – energy without heat

At atmospheric pressure, plasma is very hot – as in flames and arc discharge. If pressure is reduced to e.g. 100 Pa, plasma can be produced at low temperatures. This is so-called cold plasma or, more precisely, non-thermal plasma.

The material, treated with low-pressure plasma, is only slightly heated because the gas has a very low temperature. However, the energy of the electrons corresponds to a temperature of several 1,000 K. This advantage enables the treatment of e.g. plastic or other temperature-sensitive materials.