  This Technical Design Report presents a detailed description of all aspects
of the LUXE (Laser Und XFEL Experiment), an experiment that will combine the
high-quality and high-energy electron beam of the European XFEL with a
high-intensity laser, to explore the uncharted terrain of strong-field quantum
electrodynamics characterised by both high energy and high intensity, reaching
the Schwinger field and beyond. The further implications for the search of
physics beyond the Standard Model are also discussed.
