A new concept of y-ray telescope. LArGO: Liquid Argon Gamma-ray Observatory

LArGO (Liquid Argon Gamma-ray Observatory) consists of a new design for a $\gamma$-ray telescope, which exploits the idea of using a Liquid Argon Time Projection Chamber (LAr-TPC) as tracker-converter. Particle tracking in LAr-TPC can efficiently starts since the primary photon vertex. Indeed, while in the present space telescopes the incident photon converts in a tungsten foil, which is a passive material, in a LAr-TPC this conversion happens in LAr itself, which is fully active. In this proceeding is described a plausible design for the tracker-converter detector which fulfills the constraints on conversion efficiency, angular resolution, and wide field of view. It is demonstrated how this design can provide an unprecedented angular resolution for a $\gamma$-ray telescope, leading to a significant improvement in sensitivity and most important disclosing the possibility to detect the polarization of $\gamma$-ray emission.