2024/04/18 by M. Soldani, Soldani, Mattia, P. Monti-Guarnieri +65
Engineering · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Radiation Detection and Scintillator Technologies #Terahertz technology and applications
paper · pdf · doi:10.48550/arxiv.2404.12016
openalex publication_date 2024/04/18 · openalex created_date 2024/04/20 · openalex updated_date 2026/07/28
A particle traversing a crystal aligned with one of its crystallographic axes experiences a strong electromagnetic field that is constant along the direction of motion over macroscopic distances. For e^± and γ-rays with energies above a few GeV, this field is amplified by the Lorentz boost, to the point of exceeding the Schwinger critical field E0 ∼ 1.32 × 1016~V/cm. In this regime, nonlinear quantum-electrodynamical effects occur, such as the enhancement of intense electromagnetic radiation emission and pair production, so that the electromagnetic shower development is accelerated and the effective shower length is reduced compared to amorphous materials. We have investigated this phenomenon in lead tungstate (PbWO4), a high-Z scintillator widely used in particle detection. We have observed a substantial increase in scintillation light at small incidence angles with respect to the main lattice axes. Measurements with 120-GeV electrons and γ-rays between 5 and 100~GeV demonstrate up to a threefold increase in energy deposition in oriented samples. These findings challenge the current models of shower development in crystal scintillators and could guide the development of next-generation accelerator- and space-borne detectors.