Generalized Budden resonance tunnelling, with application to linear conversion nearly parallel to magnetic field

A model of linear wave conversion problems is formulated, which forms a natural generalization of the Budden resonance tunnelling model. The structure of the model is such as to conserve energy flux, and also is such as to allow explicit solution in terms of contour integrais. An arbitrary number of wave modes may participate. Explicit expressions for the conversion coefficients in terms of quantities derivable from the dispersion relations are obtained. A standard way of extending the model, by which resonant absorption is retrieved as conversion into an additional short wave mode, is included. The formulae obtained, are shown to include a complete solution to the problem of linear conversion in a magnetized plasma when the waves are nearly parallel to the magnetic field.