4. Non-equilibrium thermal plasmas

4.1 Conditions of non-equilibrium

In the highly ionized zones of thermal plasmas (percentage of electrons greater than 1%), i.e. with electron densities greater than 5 × 10 ²² m ^-3 ), the temperature of the heavies is generally close to that of the electrons (cf. equation (5) ). This is not the case in areas of high concentration gradients, i.e. at the periphery of a plasma or plasma jet (extinction plasma), or in the vicinity of a wall. This is because diffusional phenomena