Reduction of uncertainties concerning fission chambers measurements through a better understanding of the calibration process and the dead time phenomenon

Fission chambers are devices widely used in the zero power facilities of the CEA within the scope of the various experimental programs conducted in the Cadarache center. Those detectors gave commonly good quality results; however, improvements could still be done to enhance them. It concerns in particular the behaviour of the chamber itself as well as the modelling of the downstream electronics. Within this framework a PhD work has been launched by the SPEx/LPE in order to improve that knowledge and to reduce the uncertainties linked to the measurements performed. Two major issues are to be addressed first, the calibration process of the fission chambers and the dead time phenomenon.