The design of the ILD AHCAL is optimized to make the best use of the PFA and its active layers are composed of about eight million scintillator tiles readout by SiPMs. If there is optical crosstalk between the tiles, the calorimeter performance can be worsened. Simulation studies on the effect of the optical crosstalk on the calorimeter performance were performed to define the requirement for the active layer design.
Comment: 7 pages, 12 figures. Talk presented at the International Workshop on Future Linear Colliders (LCWS2017), Strasbourg, France, 23--27 October 2017. C17-10-23.2