Steady-state protogalactic CR proton (primary) and electron (secondary) profile integrated over all energies for a SN rate ℛ_SN = 0.1 yr⁻¹. The blue line shows the profile for electrons, while the black line corresponds to protons. The solid part of the black line is the proton distribution within the interstellar medium of the protogalaxy, where the magnetic field model is more robust. Outside the protogalaxy, the magnetic field is less well understood and so our result (the dashed part of the black line) should be regarded as an upper limit.¹⁰