# Simulation studies of annihilation-photon's polarisation via Compton scattering with the J-PET tomograph

## TL;DR

This study explores how the J-PET tomograph, made of plastic scintillators, can determine the polarization of 511 keV annihilation photons through Compton scattering, highlighting physical limits to measurement accuracy.

## Contribution

It provides the first estimates of the physical limitations in polarization measurement accuracy of annihilation photons using the J-PET detector.

## Key findings

- Identified the dominant Compton scattering interactions at 511 keV in plastic scintillators.
- Estimated the physical accuracy limits for polarization determination with J-PET.
- Demonstrated potential for polarization studies in PET imaging using plastic scintillators.

## Abstract

J-PET is the first positron-emission tomograph (PET) constructed from plastic scintillators. It was optimized for the detection of photons from electron-positron annihilation. Such photons, having an energy of 511 keV, interact with electrons in plastic scintillators predominantly via the Compton effect. Compton scattering is at most probable at an angle orthogonal to the electric field vector of the interacting photon. Thus registration of multiple photon scatterings with J-PET enables to determine the polarization of the annihilation photons. In this contribution we present estimates on the physical limitation in the accuracy of the polarization determination of $511$~keV photons with the J-PET detector.