Towards the demonstration of photon-photon collision with compact lasers

TL;DR

This paper proposes a compact laser-based setup to observe photon-photon collisions and generate electron-positron pairs via the Breit-Wheeler process, using plasma interactions and high-brilliance X-ray pulses.

Contribution

It introduces a novel, compact laser-driven method to demonstrate the two-photon Breit-Wheeler process with detailed simulation results.

Findings

Production of over 3×10^11 X-ray photons per shot.

Generation of more than 1.1×10^5 electron-positron pairs per shot.

Positrons can be transversely accelerated for detection.

Abstract

We report a proposal to observe the two-photon Breit-Wheeler process in plasma driven by compact lasers. A high charge electron bunch can be generated from laser plasma wakefield acceleration when a tightly focused laser pulse transports in a sub-critical density plasma. The electron bunch scatters with the laser pulse coming from the opposite direction and results the emitting of high brilliance X-ray pulses. In a three-dimensional particle-in-cell simulation with a laser pulse of $\sim$10 J, one could produce a X-ray pulse with photon number higher than $3\times10^{11}$ and brilliance above $1.6\times 10^{23}$ photons/s/mm$^2$/mrad$^2$/0.1$\%$BW at 1 MeV. The X-ray pulses collide in the plasma and create more than $1.1\times 10^5$ electron-positron pairs per shot. It is also found that the positrons can be accelerated transversely by a transverse electric field generated in the plasma, which enables the safe detection in the direction away from the laser pulses. This proposal which has solved key challenges in laser driven photon-photon collision could demonstrate the two-photon Breit-Wheeler process on a much more compact device in a single shot.