Realising single-shot measurements of quantum radiation reaction in high-intensity lasers

Abstract

Modern laser technology is now sufficiently advanced that collisions between high-intensity laser pulses and laser-wakefield-accelerated (LWFA) electron beams can reach the strong-field regime, so that it is possible to measure the transition between the classical and quantum regimes of light-matter interactions. However, the energy spectrum of LWFA electron beams can fluctuate significantly from shot to shot, making it difficult to clearly discern quantum effects in radiation reaction (RR), for example. Here we show how this can be accomplished in only a single laser shot. A millimetre-scale pre-collision drift allows the electron beam to expand to a size larger than the laser focal spot and develop a correlation between transverse position and angular divergence. In contrast to previous studies, this means that a measurement of the beam's energy-divergence spectrum automatically distinguishes components of the beam that hit or miss the laser focal spot and therefore do and do not experience RR.

Radiation reaction in electron–beam interactions with high-intensity lasers

“…2), allowing us to examine critically our theoretical and simulation approaches to the modelling of particle dynamics in strong electromagnetic fields. The current mismatch between simulations and experimental data has prompted, and will continue to prompt, new ideas in how to resolve the discrepancy: from the development of analysis techniques that are robust against shot-to-shot fluctuations [177,178], to improved simulation methodologies [116,117]. These are accompanied by renewed examination of the approximations underlying our simulations (see section III C).…”

Exact solutions in radiation reaction and the radiation-free direction

“…Despite having been studied for more than a century [1][2][3], radiation reaction (RR) continues to attract theoretical [4][5][6][7][8][9], computational [10,11], and experimental [12][13][14][15] interest. In large part, this attention is driven by intense laser systems [16][17][18][19] now granting access to regimes where quantum and classical RR forces can dominate the Lorentz force.…”

“…FIG.1. Momentum transfer W(14), in a head-on collision with a Sauter pulse with a0 < 0. Without RR, the momentum transfer is unbounded.…”

Quantum anti-quenching of radiation from laser-driven structured plasma channels

“…Earlier studies of quantum RR in collisions of highly relativistic electrons with ultra-intense laser pulses [31][32][33][34] analyzed spectral [35][36][37], as well as angular signatures of RR [38]. Consequently, elaborately optimized experimental tests were proposed [39,40] and large-scale plasma simulations performed, including an approximate account for stochastic QED effects [7,8,41,42].…”