Abstract: The time-asymptotic distribution function of continuously created newborn and pickup ions in solar wind is obtained by solving the quasilinear kinetic equation in which we have assumed that the turbulence consists mainly of Alfvén waves. The stability analysis of obliquely propagating Alfvén waves is carried out.The distribution function is found to be anisotropic in velocity space and consequently can result in the excitation of Alfvén waves via wave-particle interaction processes. The growthrate Is the highest in the case of parallel propagation.