Speaker
Description
Background reduction is critical for achieving high signal-to-noise ratios in neutron scattering instruments, yet mitigation strategies have historically relied on empirical practices and accumulated experience rather than on systematic, quantitative analysis. Instrumental background typically arises from multiple interacting sources associated with shielding, structural components, and the experimental environment, making its characterisation particularly challenging.
This work presents initial steps towards the development of a rigorous and reproducible framework for background analysis and engineering, motivated by the current and future instrument needs at the European Spallation Source (ESS), which is preparing to commence operations in Lund, Sweden.
A simplified instrument cave is employed as a controlled test case to isolate fundamental background mechanisms and to investigate the effects of different shielding configurations and material choices. Several commonly used design concepts are assessed using both monoenergetic neutrons and broad energy spectra representative of spallation facilities.
Although the present results are not intended to optimise a specific instrument, they establish a foundation for the systematic testing, decomposition, and quantification of the "tribal knowledge" commonly applied in neutron instrument design. Future work will extend this methodology to more realistic geometries and to targeted experimental validation in collaboration with the ESS instrument teams.