Breakdown threshold in the microwave field at low and high pressures in electronegative gas mixtures

The dependence of the critical value of the microwave field amplitude in electronegative mixtures, which corresponds to the local equality of the ionization frequency and the dissociation attachment frequency, is investigated theoretically in a wide range of pressures with allowance for electron temperature pulsations. The resultant values are compared with the critical value for the static field. The range of pressures in which electron temperature pulsations become significant is determined, and the excess of the critical amplitude over the value in the static field is calculated in the high-pressure limit. Simple formulas are recommended for estimating the critical value of the microwave field amplitude.