Stochastic acceleleration has been unimportant inside the solar wind termination shock. This is due to the fact that, its characteristic time is much larger than the time for particle propagation in this region. However, in the heliosheath, where the turbulence in the heliospheric magnetic field increases with the radial distance and the solar wind speed decreases as it moves out, the acceleration time for stochastic process become shorter than convection time of the solar wind. In this work we analyse the anomalous cosmic ray modulation using a self-consistent model of the Parker transport equation, that includes an stochastic acceleration. We conclude that this mechanism,amongst several others, could make a contribution to the spectral shapes of anomalous cosmic ray component.

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 1 (SH), pages 865-868