Physics in Intense Fields (PIF24)

Spectral and spatial high-resolution characterisation of high-flux and high-energy gamma-ray beams from intense laser-electron beam interactions

29 Aug 2024, 14:30

25m

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General Talk 4

Speaker

Prof. Gianlucca Sarri (Queen's College Belfast)

Description

At the frontier of ultra-high electromagnetic intensities, it is now possible to access peak laser intensities of up to ∼ ${10}^{23}$ W/cm${}^2$ [1], with even higher intensities envisaged at upcoming multi-petawatt class facilities [2]. The interaction of an ultra-relativistic electron beam with electromagnetic fields of this magnitude represents an ideal experimental configuration to access unexplored regimes of strong-field quantum electrodynamics (SFQED), where the transition from perturbative to non-perturbative processes, as well as the transition from classical to quantum dynamics, occurs [3,4]. Remarkably, formulation and calculation of a first-principle and accurate theory for the dynamics of an electron in an external electromagnetic field of arbitrary intensity is still one of the most fundamental outstanding problems in electrodynamics. The spectral and spatial properties of the Compton photon beams [5] during this type of interactions are known to carry precious information on the interaction; however, a high-resolution detection of the spatial and spectral distribution of such photon beams is experimentally challenging due to their high energy per photon and their high flux.
Here we present the recent development of a high-energy gamma-ray spectrometer [6,7] and a gamma-ray profiler [8,9] suited for this challenging task. Numerical modelling and proof-of-concept experimental tests indicate the possibility of measuring the spectrum and spatial profile of GeV-scale gamma-ray beams with %-level and micron-scale precision, respectively. These diagnostics will be included in several SFQED experimental platforms [10,11] and are expected to represent key diagnostics for this class of experiments.

[1] J. W. Yoon et al., Optica 8,630 (2021)
[2] C. N. Danson et al., High Power Laser Sci. Eng. 7,e54 (2019)
[3] K. Poder et al., Phys. Rev. X 8, 031004 (2018)
[4] J. Cole et al., Phys. Rev. X 8, 011020 (2018)
[5] G. Sarri et al., Phys. Rev. Lett. 113, 224801 (2014)
[6] K. Fleck et al., Scientific Reports 10, 9894 (2020)
[7] N. Cavanagh et al., Phys. Rev. Res. 5, 043046 (2023)
[8] K. Fleck et al., Phys. Rev. A accepted (2024)
[9] P. Grutta et al., NIM-A submitted (2024)
[10] H. Abramowicz et al., Eur. Phys. J. Special Topics 230, 2445 (2021)
[11] S. Meuren et al., Probing Strong-field QED at FACET-II (SLAC E320)