Towards realistic simulations of QED cascades: non-ideal laser and electron seeding effects

TL;DR

This paper investigates how realistic laser parameters like pulse duration, timing delays, and alignment mismatches influence the development of QED cascades in laser collisions, highlighting factors crucial for experimental setups.

Contribution

It extends previous models by analyzing the effects of non-ideal laser conditions on QED cascade onset and evolution in realistic laboratory scenarios.

Findings

Pulse duration significantly affects cascade development.

Timing delays influence cascade initiation thresholds.

Misalignment between laser foci alters cascade growth.

Abstract

A number of analytical and numerical studies has been performed to investigate the onset and the development of QED cascades in the collision of two counterpropagating laser pulses as a function of the laser intensity. However, it has been recently demonstrated [M. Tamburini et al., Sci. Rep. 7, 5694 (2017)] that the onset of QED cascades is also strongly influenced by the structure of the laser pulses, such as the laser pulse waist radius. Here we investigate how QED cascades are affected by: (a) the laser pulse duration, (b) the presence of a relative delay for the peak of the laser pulses to reach the focus, (c) the existence of a mismatch between the laser focal axis of the two laser pulses. This is especially important as, in realistic laboratory conditions, fluctuations may arise in the temporal and point stability of the lasers.