Multiple colliding electromagnetic pulses: a way to lower the threshold of $e^+e^-$ pair production from vacuum

TL;DR

This paper demonstrates that using multiple focused electromagnetic pulses can significantly lower the threshold for vacuum $e^+e^-$ pair production, enabling observation with realistic laser systems.

Contribution

It introduces a realistic three-dimensional model showing how multiple pulse focusing reduces pair production threshold and creates subwavelength field features.

Findings

Lowered pair production threshold with multiple pulses

Generation of extremely short $e^+e^-$ bunches

Subwavelength field features in focal region

Abstract

The scheme of simultaneous multiple pulse focusing on one spot naturally arises from the structural features of projected new laser systems, such as ELI and HiPER. It is shown that the multiple pulse configuration is beneficial for observing $e^+e^-$ pair production from vacuum under the action of sufficiently strong electromagnetic fields. The field of the focused pulses is described using a realistic three-dimensional model based on an exact solution of the Maxwell equations. The $e^+e^-$ pair production threshold in terms of electromagnetic field energy can be substantially lowered if, instead of one or even two colliding pulses, multiple pulses focused on one spot are used. The multiple pulse interaction geometry gives rise to subwavelength field features in the focal region. These features result in the production of extremely short $e^+e^-$ bunches.