Damping of self generated Alfvén waves in a partially ionized medium and the grammage of cosmic rays in the proximity of supernova remnants

International audience; We study the damping of Alfvén waves generated by the cosmic ray resonant streaming instabilityas due to ion-neutral damping, turbulent damping and non linear Landau damping, in the warmionized and warm neutral phases of the interstellar medium. We do so in the context of the cosmicray escape and propagation in the proximity of supernova remnants. For the ion-neutral damping,state-of-the-art damping coefficients are used, where the momentum transfer and charge exchangecross sections between various species of ions and neutrals are computed in detail or measured.We investigate whether the self-confinement of cosmic rays nearby sources can appreciably affectthe grammage. In fact, if this is the case, the standard picture, in which CR secondaries areproduced during the whole time spent by cosmic rays throughout the Galactic disk, should bedeeply revisited. We show that the ion-neutral damping and the turbulent damping effectivelylimit the residence time of cosmic rays in the source proximity, so that the grammage accumulatednear sources is found to be negligible, contrary to what was previously suggested.