Linearity of the response to test beam electrons for EM Barrel module P13

During August 2002 the LArg Barrel calorimeter module P13 was exposed to monoenergetic electron beams at the H8 beam lines. The precise measurement of the beam energy allowed the detailed study of the detector response linearity in the range 10 to 180 GeV. The result critically depends on the way the detector samplings are weighted to account for the energy losses upstream and downstream the module. This problem is discussed in detail with the help of simulated data. Other reconstruction effects affecting the linearity are also discussed.