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

New results from numerical simulations of cosmic-ray modulation by the solar wind are presented. It is argued that the scattering mean free path should be larger than the particle gyroradius in the average magnetic field. Since this constraint was violated in our previous paper, we discuss here simulations which incorporate the larger diffusion, as anticipated, and the difference between drift and no-drift solutions is not so great as before. Nonetheless, we still find profound effects of the drifts. The drifts still determine the origin of the bulk of the cosmic rays seen at any given time in the inner solar system. Thus, during the 1975 solar minimum, positively charged cosmic rays seen in the inner solar system came primarily from the outer boundary near the heliosphereic poles, and negative particles came from the equatorial regions of the boundary. The situation reverses during alternate solar cycles and with the sign of the particle charge. The calculated energy spectra agree reasonably well with observations and are insensitive to the magnitude of the diffusion coefficient