A ray-based algorithm for multi-dimensional linear conversion

A numerical algorithm is proposed for connecting the incoming and outgoing wave fields in studies of linear conversion. This is the first such ray-bas ed algorithm for wave conversion in multiple spatial dimensions. It is demo nstrated that, aside from the overall phase of the coupling, one can direct ly evaluate all quantities needed for the connection coefficients from the ray geometry. The ray dynamics is generated using the determinant of the di spersion matrix as the Hamiltonian. Using information available while follo wing an incoming ray, the algorithm automatically detects that the ray has entered a conversion region, evaluates the transmission and conversion coef ficients, and launches the transmitted ray. The algorithm does not require any prior knowledge of the geometry of the conversion region. The algorithm is illustrated using a two-dimensional toroidal model with resonant conver sion from a magnetosonic to an ion-hybrid wave. (C) 2001 Elsevier Science B .V. All rights reserved.