Creating QED Photon Jets with Present-Day Lasers

TL;DR

This paper demonstrates that high-energy QED photon jets can be generated using current laser technology and simple targets, through self-forming channels induced by tightly focused laser pulses, with robust formation under various conditions.

Contribution

It introduces a method to produce high-energy QED photon jets with present-day lasers via self-forming channels in targets, validated by simulations and historical shot data.

Findings

High-energy photon jets with flux of 10^12 sr^-1 can be created.

Self-forming channels are robust to experimental variations.

Detectable photon flux requires about 60 J in a 150 fs pulse.

Abstract

Large-scale, relativistic particle-in-cell simulations with quantum electrodynamics (QED) models show that high energy (1$<E_\gamma\lesssim$ 75 MeV) QED photon jets with a flux of $10^{12}$ sr$^{-1}$ can be created with present-day lasers and planar, unstructured targets. This process involves a self-forming channel in the target in response to a laser pulse focused tightly ($f$ number unity) onto the target surface. We show the self-formation of a channel to be robust to experimentally motivated variations in preplasma, angle of incidence, and laser stability, and present in simulations using historical shot data from the Texas Petawatt. We estimate that a detectable photon flux in the 10s of MeV range will require about 60 J in a 150 fs pulse.