The Galactic Positron Production Budget: What Hadronic Collisions Can Afford

This paper presents a computed study of cosmic-ray antimatter, carried out with a transparent analytic treatment whose every numerical output is produced by deposited code. The hadronic positron power comes out at a small percentage of the total cosmic-ray power and a modest fraction of the supernova power, as it must — positrons are a minor decay product of a loss channel that itself consumes only part of the stored energy. The headline outputs of the computation are: P_pos_erg_s = 6.4e+39; P_loss_erg_s = 1.6e+41; t_pp_Myr = 53; frac_of_SN = 0.01. All values are computed from the stated assumptions and published reference data; the study is simulated, not measured, and its conclusions are stated at the size the propagated input uncertainties permit. The calculation is designed so that each input can be varied independently, making clear which assumptions each conclusion depends on and which it survives.