Polarimetry of the L alpha Line for Coronal Magnetic Field Diagnostic

Measurement and physical interpretation of the scattering polarization of the Extreme-ultraviolet (EUV) and Far-UV (FUV) spectral lines provide a largely unexplored diagnostic of coronal magnetic field. In this context, we present the LYOT (LYman Orbiting Telescope) project that makes it possible to observe the La lambda 1216 line polarization in the solar corona. Because the corona is optically thin, it is necessary to consider the effects of the integration over the line-of-sight (LOS). The LOS effects have been usually addressed for non polarimetric studies where the unknown is a scalar quantity (the intensity) but riot a Stokes vector. Previous studies investigating the coronal polarization are generally concerned with a local position of the scattering center and a deterministic magnetic field (see Raouafi et al. 2002 for a measurement and interpretation of the O VI lambda 1032 line polarization). Here, we perform computations that test whether a LOS integrated Hanle effect can be detected in order to access to the magnetic field topology.