Study on the structure of local Alfven resonance and the Alfven wave absorption in toroidal plasma

It is studied theoretically and experimentally the structure of local Alfven resonance (AR) and the absorption of Alfven waves (AW) in nonuniform plasma without ohmic current. Expressions are obtained for rf-field distribution in the AR region and for the power absorbed by plasma taking into account finite Larmor radius of ions, inertia of electrons, gyrotropic effect and Cherenkov wave absorption by elecrt electrons, Amplitude and phase measuring of electric and magnetic rf-field components in the AR region for travelling and standing waves have been carried out at the OMEGA toroidal installation in currentless plasma. It is shown the existence of discrete spectra of resonance surfaces in the region near calculated AR values for toroidal AW modes. The AW absorption in the AR region and the dynamics of plasma production with the help of AW have been studied experimentally. The definitive influence of the AR surfaces on the profile and the value of produced plasma density is shown