It is associated with relativistic electrons or cosmic ray electrons, so named because they travel at speeds comparable with that of light.
But the incoming cosmic ray flux, which would otherwise be isotropic, is shaped by the Earth's magnetic field.
The spark chamber shows clearly the tracks of charged particles - in this case, mainly cosmic ray muons from outer space.
The implications for high energy neutrino, gamma ray and cosmic ray production in GRB and AGN jets are discussed.
The assumption of charge independence is used to calculate production by cosmic ray neutrons using spallation cross sections for proton induced reactions.
