Neutron noise methods based on the fluctuations of the nuclear chain reaction (i.e. zero noise) have been used for reactor physics measurements since the early ages of nuclear technology. These methods can determine several important reactor kinetic parameters (e.g., reactivity, prompt decay constant, generation time). Recent developments in the field with state-of-the-art data acquisition systems promise a wider range of applicability, improved temporal resolution and reduced uncertainty of the measured data. The additional information obtained from neutron detectors with noise evaluation can be valuable in core monitoring (e.g. in subcritical conditions during refuelling) or improved core characterization for benchmark measurements.

The PhD research aims to further develop neutron noise methods by investigating the potential role in core monitoring and benchmarks for high-fidelity reactor physics calculation tools.

The candidate’s tasks will include the further development of neutron noise methods based on the continuous signal of detectors, which is more tolerant to dead-time effects and higher count rates than traditional pulse counting methods. Its range of applicability must be determined and compared with pulse counting to identify the cases where clear advantages can be expected.

Special attention will be put on the accurate measurement of higher dynamic modes and how the information obtained from them can be applied in core monitoring and characterization.

Methods will be developed for uncertainty quantification of the data and parameters obtained from neutron noise measurements.

The candidate will perform measurements to test the developed methodologies. The measurements will be primarily performed at the BME Training Reactor with improved instrumentation (high-speed data acquisition system and miniature fission chambers). International cooperation with partners from Japan and the US may extend the measurement opportunities to other facilities. The measurements will be designed and evaluated using Monte Carlo simulations. If the quality of the measured data allows, a benchmark description will be compiled for reactor physics calculation tools to reproduce integral parameters and distributions obtained from neutron noise measurements.