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| What is a plasma? | |
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Plasmas are sometimes referred to as the 4th state of matter, apart from solids, liquids and gas. Our sun is the best known example of a plasma. Typical for plasmas is the presence of charged particles: electrons, ions (both positively and negatively charged) energetic UV photons and sometimes charged dust particles.
The particles in the plasma are highly chemically reactive. The temperature of the "large" particles (atoms and molecules) in the plasma can be room temperature, but the temperature of the electrons is several thousand degrees centigrade.
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 Figure 1: The plasma needle |
Our plasma Our plasma is generated at ambient pressure under helium flow. Plasma appears at the end of a metal tip. It is a radio-frequency (rf) glow that can be controlled as hand-operated tool. Radicals that are produced with our plasma are OH and O. Possibly there is also ozone production. The plasma also emits UV radiation mainly in the 300 - 400 nm region. |