3D vector tomography using vector spherical harmonics decomposition

The article presents the reconstruction method of the flow fields from vector tomography passive ion Doppler spectroscopy in a plasma experiment. The method is based on series expansion in terms of vector spherical harmonics for volumetric, divergent-free vector fields and intended for three-dimensional diagnostic in the spherical tokamak devices. An inversion of spectral experimental data is known in tomography as an inversion of vectorial ray transform. The relation of the vectorial ray transform with Doppler spectroscopy measurements are given in Balandin and Ono (2001, 2003) [7] and [8]. The effectiveness of the proposed method is tested on a range of model 3D divergent-free vector fields.