One-dimensional full wave treatment of mode conversion process at the ion-ion hybrid resonance in a bounded tokamak plasma

A consistent picture of the mode conversion (MC) process at the ion-ion hyb rid resonance in a bounded plasma of a tokamak is discussed, which clarifie s the role of the global fast wave interference and cavity effects in the d etermination of the MC efficiency. This picture is supported by simulations with the kinetic code "VICE'' [Fraboulet et al., "One-D full-wave descript ion of plasma emission and absorption in the Ion Cyclotron Range of Frequen cy in tokamaks,'' submitted to Phys. Plasmas]. The concept of the "global r esonator,'' formed by the R = n(parallel to)(2) boundary cutoffs [Saoutic e t al., Phys. Rev. Lett. 76, 1647 (1996)], is justified, as well as the impo rtance of a proper tunneling factor choice eta(cr) = 0.22 [Ram et al., Phys . Plasmas 3, 1976 (1996)]. The MC scheme behavior appears to be very sensit ive to the MC layer position relative to the global wave field pattern. Opt imal MC regimes are found to be attainable without requirement of a particu lar parallel wave number choice. (C) 1999 American Institute of Physics. [S 1070-664X(99)03103-1].