Galactic source distribution of heavy cosmic rays and the energy dependent overabundance of 22Ne 
A. Soutoul1, R.legrain2
    1 DAPNIA/SAp CEA/SACLAY, 91191 Gif sur Yvette CEDEX, France.
    2 DAPNIA/SPhN CEA/SACLAY, 91191 Gif sur Yvette CEDEX, France.

Diffusive confinement of cosmic ray nuclei in a galactic model with cylindrical symetry is considered. Radial dependences of cosmic ray source distribution and gas distribution are adopted. The source abundance gradient of 22Ne is taken steeper than the average gradient of cosmic ray sources (Maeder A. and Meynet G, 1993,A&A 278,406). The resulting energy dependent overabundance of 22Ne in cosmic rays at the solar system is calculated. As a result of the steep source distribution of 22Ne the abundance of its secondary products (21Ne,19F, etc. ) are larger than in the exponential model (leaky box). Results of these calculations for a range of cosmic ray source gradients and gas density gradients will be presented. The future data on neon and lower isotopes from the CRIS experiment on ACE should provide interesting consraints on this model. A preliminary version of this work was presented at the 26th ICRC (Vol. 4,p 180).