STOCHASTIC REACCELERATION OF COSMIC-RAYS IN THE INTERSTELLAR-MEDIUM

The effects of reacceleration on cosmic rays have been studied over a wide charge and energy range using a model of reacceleration by the in terstellar turbulence. We take into account only inevitable stochastic reacceleration of cosmic rays by the random hydrodynamic waves, which supposedly exist in the interstellar medium and provide a means for c osmic-ray scattering and spatial diffusion in the Galaxy. Our calculat ions reproduce not only the B/C ratio but also the H and He data over the entire energy range where the measurements are available. However, the sub-Fe to Fe ratio is not fitted as well as the B/C ratio, and th e reacceleration effect does not seem to remove the need for truncatio n of short path lengths, which is apparently required by the standard leaky box model. This work demonstrates that the cosmic-ray data can b e represented at least as well by a reacceleration model with a simple rigidity power-law escape length, which agrees with the Kolmogorov-ty pe spectrum of hydromagnetic turbulence, as they can by the standard l eaky box model with its ad hoc escape lengths.