For more than a decade, the Instrumentation, Sensors and Dosimetry laboratory (LDCI) at CEA/IRESNE Cadarache has been working on the optimisation and reliability of fission chambers. Such neutron detectors are essential for the safety and operation of nuclear power plants and to perform experiments in research reactors such as the Jules Horowitz Reactor. Conversely, those applications have needs for innovative, reliable and well-understood sensors. A special focus is placed on correcting for sensor failures and on calibration procedures to increase the dependability of the measurements.
In order to meet these needs, a PhD thesis is proposed at LDCI, on the experimental study of fission chambers of the Corex type: this versatile test chamber, designed during a previous PhD to study columnar recombination, can be operated without a reactor, for a simpler access and handling. The PhD student will make use of this test device to explore the physical phenomena at stake in the signal build-up, in order to revise and qualify the corresponding models and computational tools. These tools will then be used to perform theoretical studies on the chamber failure scenarios and its calibration in fluctuation and current modes as well.
The doctoral student will develop competence in modelling and implementing nuclear instrumentation.