2025/05/24 by Pouyez, M., Nicotera, G., Galbiati, M. +4 · 1 citation
#FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Theory (hep-th) #Plasma Physics (physics.plasm-ph)
paper · doi:10.48550/arxiv.2505.18843
Electromagnetic showers from high-energy electron beams interacting with a target are a promising path to creating pair plasmas in the laboratory. Here, we solve analytically the kinetic equations describing this process. Two regimes are defined by the ratio of the target thickness L to the shower length L_\rmsh, which depends on the electron energy and target composition. For thin targets (L < L_\rmsh), we derive explicit expressions for the spectra of produced photons and pairs, as well as the number of pairs. For thick targets (L > L_\rmsh), we obtain the total pair number and photon spectrum. Analytical results agree well with Geant4 simulations, and it is found that significant pair escape requires L < L_\rmsh. The divergence, density and characteristic dimensions of the escaping pair jets are derived, and a criterion for pair plasma formation is obtained. While current laser wakefield beams are not well adapted, multi-petawatt lasers may provide new electron or photon sources suitable for laboratory pair plasma production.