Implioations of HEAO 3 data for the acceleration and propagation of galactic cosmic rays

The authors reexamine the energy dependence of the mean escape length of cosmic rays from the Galaxy in the light of recent measurements of cosmic-ray abundances from the Danish-French experiment on HEAO 3. Comparing these data with results of propagation calculations, they find that the energy dependence is steeper than previously thought. This result coupled with the absence of structure in the proton spectrum to 10¹⁴ eV, implies that 1 GeV per nucleon cosmic rays do not diffuse more than a few hundred parsecs from their sources during their 10⁷ year lifetime. The authors discuss implications for the shape of the cosmic ray path length distribution at short path lengths and on the galactic wind model for the loss of cosmic rays from the Galaxy by convection.