Journal: Nature Communications

Article Title: Emulator-based Bayesian inference on non-proportional scintillation models by compton-edge probing

doi: 10.1038/s41467-023-42574-y

Figure Lengend Snippet: a Monte Carlo mass model of the experimental setup to perform Compton edge probing with an inorganic gamma-ray scintillation spectrometer under laboratory conditions. The spectrometer consists of four individual 10.2 cm × 10.2 cm × 40.6 cm prismatic NaI(Tl) scintillation crystals with the associated photomultiplier tubes (PMT), the electronic components, e.g. the multi-channel analyzers (MCA), embedded in a thermal-insulating and vibration-damping polyethylene (PE) foam protected by a rugged aluminum detector box. We inserted radiation sources consisting of a radionuclide carrying ion exchange sphere (diameter 1 mm) embedded in a 25 mm × 3 mm solid plastic disc into a custom low absorption source holder made out of a polylactide polymer (PLA) and placed this holder on a tripod in a fixed distance of 1 m to the detector front on the central detector x -axis. The mass model figures were created using the graphical interface FLAIR . For better visibility and interpretability, we applied false colors. b Overview of the Bayesian inference framework highlighting the gamma-ray spectrometry based Compton edge probing measurements, the Monte Carlo simulations using the multi-purpose code FLUKA combined with the machine learning trained polynomial chaos expansion (PCE) emulator models supported by principal component analysis (PCA) as well as the Bayesian inference by Markov Chain Monte Carlo (MCMC) itself using UQLab . c Radiation transport mechanisms inside the inorganic scintillation crystal, which is surrounded by a thin reflector layer and a rugged aluminum crystal casing. d Schematic representation of an inorganic scintillation crystal lattice including the activator atoms and point defects. e Mechanistic depictions of the various scintillation and quenching pathways for electron-hole pairs (e − /h) as well as excitons within the inorganic scintillation crystal lattice. Adapted from ref. .

Article Snippet: For better visibility and interpretability, we applied false colors. b Overview of the Bayesian inference framework highlighting the gamma-ray spectrometry based Compton edge probing measurements, the Monte Carlo simulations using the multi-purpose code FLUKA combined with the machine learning trained polynomial chaos expansion (PCE) emulator models supported by principal component analysis (PCA) as well as the Bayesian inference by Markov Chain Monte Carlo (MCMC) itself using UQLab . c Radiation transport mechanisms inside the inorganic scintillation crystal, which is surrounded by a thin reflector layer and a rugged aluminum crystal casing. d Schematic representation of an inorganic scintillation crystal lattice including the activator atoms and point defects. e Mechanistic depictions of the various scintillation and quenching pathways for electron-hole pairs (e − /h) as well as excitons within the inorganic scintillation crystal lattice.

Techniques: Polymer