MeV-GeV polarimetry with the Fermi-LAT

A measurement of MeV-GeV linear polarization would provide information about the emission mechanisms of gamma-ray sources, especially pulsars and AGN (Active Galaxy Nuclei). The Fermi Large Area Telescope (Fermi -LAT) detects gamma rays between 20 MeV and ∼300 GeV, using their conversion into an electron-positron pair, with the linear polarization affecting the azimuthal direction of the pair. Measuring this azimuthal direction is extremely challenging due to the multiple scattering of the electron-positron pair in the detector. We present the current effort to extract the polarization information from the Fermi -LAT data, including recent developments in the simulation implementation and the event reconstruction and selection. This allows us to estimate the expected sensitivity to linear polarization of the Fermi -LAT, and we apply this to the Vela pulsar.