Theoretical modelling of CW perturbations of excited states, axialfield and electron density for laser diagnostics of positive columnplasmas

Abstract

We present a theoretical treatment of the fundamental perturbationscaused when continuous wave tunable laser radiation is absorbed by thelow-temperature plasma of a noble gas positive column. For the first time wepresent a full theoretical description of the contributions due to the inducedchanges in the electric field, electron density and radiation trapping, aswell as the primary laser perturbations. Comparison of our theory withexperimental observation shows that the primary perturbations are generallydominant but in some instances it is the field perturbation which has thegreatest effect.