Recent measurements of the cosmic ray ( CR ) antiproton flux have been shown to challenge existing CR propagation models .
It was shown that the reacceleration models designed to match secondary to primary nuclei ratios ( e.g. , B/C ) produce too few antiprotons .
In the present paper we discuss one possibility to overcome these difficulties .
Using the measured antiproton flux and B/C ratio to fix the diffusion coefficient , we show that the spectra of primary nuclei as measured in the heliosphere may contain a fresh local “ unprocessed ” component at low energies perhaps associated with the Local Bubble , thus decreasing the measured secondary to primary nuclei ratio .
The independent evidence for SN activity in the solar vicinity in the last few Myr supports this idea .
The model reproduces antiprotons , B/C ratio , and elemental abundances up to Ni ( Z \leq 28 ) .
Calculated isotopic distributions of Be and B are in perfect agreement with CR data .
The abundances of three “ radioactive clock ” isotopes in CR , ^ { 10 } Be , ^ { 26 } Al , ^ { 36 } Cl , are all consistent and indicate a halo size z _ { h } \sim 4 kpc based on the most accurate data taken by the ACE spacecraft .