EVIDENCE FOR THE DEFICIENCY OF SHORT COSMIC-RAY PATHLENGTHS AND A PHYSICALLY REALISTIC EXPLANATION - NO-NEAR-SOURCES MODEL

From our recent observations of the charge and energy spectra of cosmic-ray nuclei we have constructed secondary-to-primary charge ratios at the two ends of the charge spectrum. These ratios are found to be inconsistent with the ad hoc leaky-box model of cosmic-ray propagation which leads to an exponential pathlength distribution. Models for which the pathlength distribution function is deficient in short pathlengths provide a more consistent picture. Several of these models are investigated, both ad hoc and physical. The physical model considered here is one for which detailed galactic propagation parameters and boundary conditions are used and for which there exists no near sources of cosmic rays over a time interval corresponding to a few times the cosmic-ray age. © 1979 D. Reidel Publishing Co.