Positron Channeling in Quasi-Mosaic Bent Crystals: Atomistic Simulations vs. Experiment

TL;DR

This study uses atomistic simulations to analyze positron channeling in bent quasi-mosaic Si(111) crystals at 530 MeV, comparing results with experiments and predicting outcomes for untested orientations.

Contribution

It provides a detailed atomistic simulation approach to positron channeling in bent crystals and validates it against experimental data, offering new predictions for untested crystal orientations.

Findings

Good agreement between simulations and experimental data

Identified key processes like channeling and volume reflection

Predicted outcomes for new crystal orientations

Abstract

This paper reports on a comprehensive study of an ultra-relativistic positron beam deflection by an oriented quasi-mosaic crystal. The analysis was carried out for the positron energy of 530 MeV incident on the quasi-mosaic bent Si(111) crystal. This particular case was chosen because it has recently been studied experimentally at the Mainz Microtron MAMI. The results of the relativistic molecular dynamics simulations were compared with the experimental observations and a good agreement was found. The presence of planar channeling, de-channeling, volume reflection and volume capture processes in the angular distribution of deflected positrons for different beam-crystal alignments has been studied. Predictions have been made for certain crystal orientations for which experimental data are lacking.