Microwave interactions with plasmas

Summary form only given. The physics of EM wave interactions with plasma with and without the confining magnetic field is presented. The plasma resonance enhances the incident field to large local values. The ponderomotive force of these enhanced electric fields create density perturbations. The coupling between high frequency and low frequency waves by mode coupling and by density perturbation is presented. The laboratory results are extended to experiments in active modification of ionospheric plasmas. Resonant molecular and atomic resonances using lasers and large telescopes are used to diagnose the laboratory and ionospheric plasmas under high field excitations.