On O-X mode conversion in a cold magnetized 2D inhomogeneous plasma in   the electron cyclotron frequency range
  In this paper a reduced set of the partial differential wave equations valid in the conversion layer close to O-mode cutoff surface and accounting for the magnetic field 2D inhomogeneity with no restriction to an angle between the toroidal direction and the magnetic field direction is derived. An integral representation of a solution to the derived set of equation is given. For the particular case of small angle between O mode cut-off surface and X mode cut-off surface an explicit expressions for both the electric field components and the conversion coefficients are obtained and its properties are considered in details. 
A. Popov