Grammage (right vertical axis) and residence time (left vertical axis) of CRs as a function of their energy in three different phases of the ISM : WNM (top), CNM (middle), and DiM (bottom). Solid lines show the results obtained at different distances z_* from the center of the source: green (100 pc), blue (50 pc), red (30 pc), and black (10 pc). The shaded region marks the no-wave propagation zone. Oscillations at high energy in the CNM and DiM are due to the limited energy resolution used to reconstruct the different curves.