Ion acoustic scattering from a magnetic dipole.

We present a fluid theory for the scattering of ion acoustic waves from a magnetic dipole immersed in a weakly-collisional neutral plasma. The theory of plasma waves involves the self-consistent interaction of particles and wave modes through collective interactiion. In the vicinity of a magnetic diplole, the dynamical behavior of charged particles is very rich. In the absence of collective interaction there are significant measures of quasi-periodic, chaotic and hyperchaotic (multiple positive Lyapunov exponents) orbits. No computable approach exists to compute the wave modes in such a context. However, the fluid theory can be taken as a starting point and can be expected to correctly describe the mode spectrum in various parts of the spectrum depending on plasma conditions. The approach involves expressing the electrostatic wave equation in dipolar coordinates, and coupling to magnetic field-free solutions in the far field.. We will report progress on the construction of a scattering theory which eventually will be generalized to a kinetic description. Specific conditions will be considered which are relevant to a well diagnosed experimental configuration that is currently being assembled for the validation of the theory.