Improved positron generation via laser plasma interaction utilising target front surface architecture: A review

Abstract

Positrons are electron antiparticles that are often produced in extreme astrophysical events, such as black holes and quasars. Positron production in the laboratory is typically done through plasma-laser interactions, utilizing the Bethe-Heitler process which involves the interaction of high-energy photons with the electromagnetic fields of atomic nuclei. One of the main challenges is to improve the efficiency of laser energy conversion into electron-positron pairs. This research utilizes a silicon microwire-based target surface structure to improve the positron production efficiency in laser plasma interactions. Particle-in-cell (PIC) simulations and experiments with the OMEGA EP laser system show that target structure 1 produces 50% more positrons than a flat surface target, with the conversion efficiency of laser energy to positrons increasing to 97%. This structure enables optimal laser energy focusing, resulting in efficient high-energy relativistic electrons to create electron-positron pairs. The results of this study show significant potential in the development of particle acceleration technology and applications in high-energy physics.