Speaker
Description
Experiments searching for rare events, such as CE$\nu$NS with NUCLEUS or hypothetical Dark Matter–nucleus scattering with CRESST, are pushing the detection threshold down to sub-100 eV energies. Experiments commonly use Monte Carlo simulations, e.g. with Geant4, to characterize detector response and background. However, in the sub-100 eV energy range, the usually applied approximation of a “free particle gas” breaks down and solid-state effects must be considered.
To tackle this issue in relation to electromagnetic particle interactions, the ELOISE project has developed a workflow to (i) obtain experimental reference data via Electron Energy Loss Spectroscopy (EELS) down to $\mathcal{O}$(eV) energies, (ii) deduce Energy Loss Functions (ELFs), which naturally describe solid-state effects such as plasmons, and (iii) calculate stopping powers dE/dX from ELFs for integration into Geant4 simulations.
In this contribution, I will briefly describe the problem and outline the scope of ELOISE. The workflow will be introduced using the examples of Al2O3 and CaWO4, commonly used target materials for CRESST and NUCLEUS. After reporting the EELS reference measurements, the obtained ELF and dE/dX data will be discussed. Finally, I will show a preliminary comparison with standard Geant4 physics models and outline future applications of the ELOISE method to additional materials of interest.