Study of a large solid angle π0 detector for the test experiment of symmetry charge dd→απ0

This thesis presents the study of a large solid angle π0 detector, designed primarily for a charge-symmetry testing experiment (dd→απ0). It is a cylindrical multishell Cerenkov counter. In a first part, we review the experimental and theoretical situation of the studies about charge symmetry; past and experiments are listed, in connection with their theoretical interpretation. In a second part, we present first the principle and general design of the detector; after that, we reckon the performances of the various versions that are considered using computer-simulations. The results of tests with an electron beam is then compared with the simulations in order to assess their reliability. Finally, the arguments favouring the final choice are explained and some future experiments described