Speaker
Description
As one of the world’s leading research reactors, the Munich neutron source FRM II has a rich program in science, industry, and medicine. Modern nuclear security standards motivate intensive efforts to convert FRM II from using Highly Enriched Uranium (HEU) to Low-Enriched Uranium (LEU) fuel. This requires a deep understanding of the reactor behavior to fulfill safety restrictions and allow for experimental characterization in agreement with simulation calculations. To update the existing reactor model, flux monitor data since the first commissioning in 2004 is analyzed. Moreover, the integral and differential neutron flux at the exit of the two neutron guides SR-4a and SR-10 will be measured using time-of-flight spectroscopy and gold-foil activation during the upcoming reactor commissioning in summer 2026. Therefore, an optimized chopper setup is designed to perform precise and absolute flux measurements of the thermal reactor spectrum between 1 and 8 Å. Stand-alone gold-foil activation measurements are planned at additional neutron guides. The experimental results can be used to benchmark today’s simulation studies based on MCNP and McStas. This will allow for validation and optimization of existing reactor models, not only for FRM II, but for nuclear reactors in general.
