Parts | Days | Selection | Search | Updates | Downloads | Help

KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur

KFM 9: Microscopy and Tomography with X-ray Photons, Electrons, Ions and Positron

KFM 9.4: Talk

Wednesday, March 29, 2023, 10:00–10:20, POT 106

Optimising the scintillator geometry for positron annihilation spectroscopy - A GEANT4 Simulation — •Dominik Boras — Chair of chemical technology and material synthesis, Würzburg, Germany

To better understand the efficiency and the role of backscattering events of a Positron annihilation lifetime spectrometer, a GEANT4 simulation of the atomic processes is conducted. The gamma quanta from the radioactive decay of 22-Na and from the annihilation positron are detected by a scintillator-photomultiplier combination. In the basic setup of the simulation, as scintillation material plastic BC422Q- 0.5wt.% was used due to its good energy resolution. Different geometries of the scintillator (box, cone, pyramid and tube) were simulated and their influence on the detection efficiency and the instrument resolution function was investigated. Furthermore, the influence of the measured sample material (density, atomic number) on the scattering of gamma quanta was considered.