Mode Conversion To Ion-Bernstein Waves Of Fast Alfven Waves With Poloidal Wavenumbers In Sheared Magnetic Fields

Previous theoretical analysis [1] of mode conversion of fast Alfven waves (FAW) to ion-Bernstein waves (IBW) neglected poloidal variations of the fields and magnetic shear. Full-wave codes show incident FAW fields focused into multiple poloidal modes near the ion-ion hybrid resonance (MR)[2]. A new mode conversion model has been constructed including poloidal wavenumbers and poloidal magnetic field. The model consists of two coupled equations for the perpendicular components of the FAW electric field. These equations are numerically integrated to find the fraction of FAW power resonantly absorbed at the IHR. When the high-field-side right-hand cutoff is included, nonzero poloidal wavenumbers can change the triplet resonator phase and improve mode conversion at low k(parallel to).