# Polarization effects in bound-free pair production

## TL;DR

This paper theoretically investigates how bound-free electron-positron pair production in gamma-ray and ion interactions results in strongly polarized positrons and ions, using relativistic quantum calculations across various ion types and energies.

## Contribution

It provides a detailed relativistic analysis of polarization effects in bound-free pair production, highlighting its potential as a source of polarized particles.

## Key findings

- Bound-free pair production can generate strongly polarized positrons.
- Polarization depends on ion charge and photon energy.
- Results applicable to both low- and high-Z ions.

## Abstract

We present a theoretical study of bound-free electron-positron pair production in the interaction of $\gamma$-rays with bare ions. Special attention is paid to the longitudinal polarization of both the emitted positrons and the produced hydrogen-like ions. To evaluate this polarization we employed exact solutions of the relativistic Dirac equation and treat the electron-photon coupling within the framework of first-order perturbation theory. Detailed calculations have been performed for both, low- and high-Z ions and for a wide range of photon energies. The results of these calculations suggest that bound-free pair production can be a source of strongly polarized positrons and ions.