Plasma Diagnostics: Revealing the Inner Workings of a Plasma

摘要

The light of ever-changing non-tangible plasmas fascinates children and adults alike. It's a love-hate relationship as fire and lightning are feared as much as their benefits are cherished. For a long time, efforts to understand a plasma where limited to looking at its light emission. Presently a large variety of plasma parameters can be determined with unbelievable accuracy. They allow an unprecedented view into the inner workings of a plasma, showing that they are even more complex than previously envisioned Plasmas are often regarded as exotic phenomena. Natural plasmas like stars, lightning or the aurora borealis are awe-inspiring. It is less known that plasmas play a key role in many aspects of our day-to-day life. For starters the lamps in our offices, on our streets and the energy saving lamps at home all are plasmas. Plasma light emission is also used in plasma televisions, gas lasers and extreme-uv (13 nm) sources for lithography. The specific non-equilibrium plasma chemistry is used in large variety of industries. This includes not only the production of computer chips, but also water and gas cleaning; surface treatments like hardening and cleaning of metals and ceramics; change of textile structure; deposition of thin film transistors, solar cells and protective polymer coatings. In addition new applications like plasma thrusters for satellites and interplanetary travel and plasma based micro-surgery (fig. 1) will soon be commonplace, whereas fusion plasmas may in future quench our energy needs.