Streaking at high energies with electrons and positrons

TL;DR

This paper proposes a novel detection scheme for high-energy gamma-ray pulses that can operate at zeptosecond timescales and MeV energies, surpassing current attosecond techniques by utilizing electron-positron pair production.

Contribution

It introduces a new method based on high-energy pair production for characterizing gamma-ray pulses at unprecedented energy and time scales.

Findings

The scheme can potentially measure gamma-ray pulses down to zeptoseconds.

It is feasible with upcoming Extreme Light Infrastructure laser facilities.

The method overcomes limitations of atomic shell physics in attosecond metrology.

Abstract

A detection scheme for characterizing high-energy $\gamma$-ray pulses down to the zeptosecond timescale is proposed. In contrast to existing attosecond metrology techniques, our method is not limited by atomic shell physics and therefore capable of breaking the MeV photon energy and attosecond time-scale barriers. It is inspired by attosecond streak imaging, but builds upon the high-energy process of electron-positron pair production in vacuum through the collision of a test pulse with an intense laser pulse. We discuss necessary conditions to render the scheme feasible in the upcoming Extreme Light Infrastructure laser facility.