Measurement of the uniformity of ALEPH electromagnetic calorimeter by using the cosmic ray

After a description of the ALEPH experiment and a detailed description of the electromagnetic calorimeter, the author of this research thesis indicates the requirements which this sensor must meet, presents the adopted solution, describes the operation principle, the structure and the construction method. A focus is made on factors which may impact uniformity. The general issue of calibration of such a sensor is addressed, and different methods of inhomogeneity measurement are described. The cosmic ray bench test and test procedure are described. After having indicated the expected muon spectrum, the author describes how these muons deposit their energy in the calorimeter, and introduces the simulation program which is used to study some systematic effects. The whole signal processing chain is described, from signal measurement to inhomogeneity mapping. Systematic effects which affect the signal are studied, and the author describes corrections to be introduced to obtain a measurement of inhomogeneity. Inhomogeneity maps are analysed. Results obtained by cosmic tests are presented and compared with other inhomogeneity measurement methods