Strong-field quantum electrodynamics in the field of ultra-intense lasers

However, QED in strong background fields remains less explored experimentally due to the challenges in generating such environments. Theoretical studies have proposed various processes and calculation frameworks in this regime, but experimental validation is essential to improve theoretical understanding.<br><br>To this end, experiments using ultra-intense laser fields or strong nuclear fields of crystals have been proposed, aiming to probe strong-field QED via the detection of emitted particles.

These studies demand advanced detectors capable of withstanding extreme high-energy and high-flux conditions.<br><br>This thesis presents the development of two such detection techniques. Firstly, a gamma-ray spectrometer, designed to measure the energy spectra of high flux and energy photon beams is discussed, detailing its operation principles and simulation studies of its expected performance. A first experimental characterisation of the spectrometer is also presented, which involved the measurement of a ~1 GeV bremsstrahlung source.<br><br>Secondly, an approach to inferring interaction properties from the spatial profile of a Compton-scattered photon beam is presented.