Electromagnetic inverse profiling for plasma diagnostics in compact microwave-based ion sources

In this paper the problem of plasma diagnostics is faced as the solution of a one-dimensional single-view multi-frequency electromagnetic inverse scattering technique. The aim of the problem is to provide effective means for plasma diagnostics by considering the dispersive properties of such medium. The inverse profiling, assessed against full-wave simulated data dealing with reliable benchmarks for microwave imaging, is carried out by exploiting a first order linearized method (Rytov approximation) and Compressive Sensing based approaches in order to attain reconstruction as reliable and accurate as possible. The recovered 1D-plasma density profile allows to complete line-integrated densities measurements already performed by microwave interferometry and polarimetry system VESPRI at INFN-LNS in Catania. This may represent a promising powerful tool for probing plasmas in very compact magnetic traps such as Electron Cyclotron Resonance Ion Sources and open the way to new facilities in plasma microwave diagnostics.