Magnetic fields in prominences: Inversion techniques for spectropolarimetric data of the He I D₃ line

We propose the use of principal component analysis (PCA) to invert spectropolarimetric data from prominences. Observation of the full Stokes profiles in prominences is very important for a deeper understanding of magnetic-field topology in these solar structures, and for the testing of theoretical models. The line formation problem, however, is complicated by the special conditions of prominences: anisotropy of light, low magnetic intensities, temperature and density ranges, etc. We created a code to solve this problem in the limit of optically thin plasma and of a collisionless regime, and use it in combination with PCA techniques to invert synthetic data. The results show that inversion is feasible.