where $B(r,\theta,z)$ is sum of strengths of the non-turbulent components. We neglected all possible interactions of particles with matter and we kept the energy of particles constant.

Our Galaxy model has the following geometrical boundary: the bulge is a symmetric ellipsoid with a major axis in the Galactic midplane 3 kpc long and a minor axis of 2 kpc. Around the bulge there is a thin cylinder with a radius of 15 kpc and the height of 500 pc. Starting positions of particles reside in the Galactic plane inside an annulus with radii of 3 and 12 kpc. This assumption is in the agreement with the observed positions of supernovae remnants ([@green]), which are the most probable sources of CRs below the knee in our Galaxy[^13].

As [@gaisser00] and [@brunetti] have shown, the average time spent in the Galaxy by cosmic ray of energy within the range $(1\div100)\times10^9$ eV is $\tau\sim 10^{14}$ s. The energy dependence of $\tau$ can be measured by comparing the spectrum of the secondary nuclei to that of the parent primary nuclei. From observation one can deduce that at least in the range $10^{10}\div10^{12}$ eV, the mean residence time varies approximately as $R^{-0.6}$ ([@garcia], [@swordy] and 