The ionization degree of a plasma is given by the Saha equation, which depends o

Question

The ionization degree of a plasma is given by the Saha equation, which depends on the temperature and the particle specific ionization energy. In thermal equilibrium, the relation between ionization and its electric potential is given by the Boltzmann relation.

It is common practice to induce a plasma via electric voltage (for example in Neon lamps), and there are also configurations with periodically applied electric fields, such as the dielectric barrier discharge.

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From what I understand, the idea is to induce polarization and consequently electrical breakdown of the gas (how does this work?), and raise the temperature via an electrical arc (is this already the plamsa?).

My question is:

In artificially generated plasmas what is the quantitative relation between the applied electric field/voltage and the ionization?

I'd also be interested in the time dependence of the plasma on the applied field frequency.

Explanation / Answer

And indeed it fills books. Look Y.P. Raizer, Gas Discharge physics. It will answer everything you would ever need.

To make a short answer, the Saha equation works well for plasmas at thermal equilibrium. These plasmas you call "artificial plasmas" are gas discharge plasmas, and they are non-equilibrium. While the gas has almost the same temperature as it had before the discharge took place, the electrons are "very hot", tens of thousands of

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