Anisotropy induced wave birefringence in bounded supercritical plasma confined in a multicusp magnetic field

摘要

Laboratory observation of rotation of the polarization axis (θ_c~20°-40° with respect to vacuum) of a penetrating electromagnetic wave through a bounded supercritical plasma (plasma frequency ω_p > wave frequency ω), confined in a multicusp magnetic field is reported. Birefringence of the radial and polar wave electric field components (E_r and E_θ) has been identified as the cause for the rotation, similar to a magneto-optic medium, however, with distinct differences owing to the presence of wave induced resonances. Numerical simulation results obtained by solving the Maxwell's equations by incorporating the plasma and magnetostatic field inhomogeneities within a conducting boundary shows a reasonable agreement with the experimental results.