Response uniformity of the ATLAS electromagnetic endcap calorimeter

The construction of the ATLAS electromagnetic endcap calorimeter modules is completed. Along the production, three of them were exposed to beam to check the electron response reproducibility and assess the detector response uniformity. Excluding the small crack region around $\eta=2.5$, studied separately, the response non-uniformity over the whole detector acceptance is around or below 0.6% for the three tested modules. The global constant term of the energy resolution over this large area is around 0.7\%, meeting the challenging ATLAS requirements despite the complex geometry of the detector. To achieve this result, corrections for high voltage, leakage and geometrical effects have been parametrized in pseudorapidity over the complete acceptance ($1.375<\eta<3.2$). They are reproducible from one module to another and can be used at the ATLAS starting time for all modules.