Anomalous Absorption of X2-Driver Pump Power in DIII-D Tokamak Plasma Via Relativistic Electron Bernstein Modes and Lower Hybrid Waves

Recently\footnote{V. Stefan. Anomalous Absorption of R-E-B Modes Due to Raman and Brillouin Scattering, and Two EB-Mode Decay of X2-Driver in DIII-D Tokamak Plasma.16$^{th}$ Topical Conf. on RF Power in Plasmas [Park City, 2005]V. Stefan. Enhanced Thermonuclear Yield Due to Low-Harmonic REB Modes in Spherical Tokamak Plasmas. Sherwood-2005 [Stateline, Nevada, USA]} I have reported on anomalous absorption of relativistic electron Bernstein modes (R-E-B) for various driver-plasma parameters in Spherical Tokamaks and DIII-D Tokamak. plasma. Here I focus on X2-Driver Pump decay in DIII-D Tokamak plasma involving lower-hybrid waves (LHW).This channel involves the Brillouin scattering of X2-Mode into another (X2)'-mode coupled to the lower-hybrid waves (LHW). The nonlinearly generated (X2)'-Mode propagates toward the second harmonic electron cyclotron layer, whereby it is absorbed through R-E-B-Mode conversion, as in case of linear propagation-absorption channel. This leads to a strongly localized absorption. The weak LHWs are collisionally absorbed in the dense plasma region transferring the energy to ion plasma component---bulk plasma heating. The secondary decays of X2, X1, and EB modes, are taken into account in evaluation of energy confinement time in multi-ion plasmas