Figure 4: Charge neutrality is spatially uniform across the leptonic beam.
From: Generation of neutral and high-density electron–positron pair plasmas in the laboratory
Normalized spatial distribution of the electrons (a) and positrons (b) at the rear surface of a 2.5 cm Pb foil, as simulated using FLUKA (details of the simulation in the Methods section). (c) Resulting spatially resolved percentage of positrons in the leptonic beam. The positron percentage oscillates between 45 and 49% across the whole leptonic beam. (d) Simulated spectrum of the electrons (solid green line) and positrons (dashed brown line) at the rear surface of the 2.5 cm Pb foil. Charge imbalance is found only in the low-energy part of the spectrum (energy of the order of 5 MeV).
