The scattering of charged particles by magnetic irregularities

The equations of motion of a charged particle are integrated through an irregularity in a large-scale magnetic field. The scattering of the particle is shown to diminish as the cyclotron radius of the particle becomes either large or small compared to the scale of the irregularity and to have a maximum when the radius is comparable to the scale. When the cyclotron radius is large, the order of magnitude of the scattering depends on the number of sequential reverse bends in the lines of force through the magnetic irregularity. It is important for the understanding of modulation of the cosmic-ray intensity by the solar wind to determine the degree of correlation between adjacent bends in the irregularities in the interplanetary magnetic field.