Effects of particle drift on the transport of cosmic rays. IV - More realistic diffusion coefficients

Results from numerical simulations of cosmic-ray modulations by the solar wind are presented which show that the scattering mean free path should be larger than the particle gyroradius in the average magnetic field. It is found that the difference between drift and no-drift solutions is not as great as in previous simulations, which violated the mean free path constraint stated. Profound effects are still noted for the drifts, which determine the origin of the bulk of the cosmic rays seen at any given time in the inner solar system. Accordingly, during the 1975 solar minimum, the positively charged cosmic rays seen in the inner solar system came primarily from the outer boundary near the heliospheric poles while negative particles came from the equatorial regions of the boundary.