The dependence of solar modulation on the sign of the cosmic ray particle charge

ISEE-3 spacecraft cosmic ray telescope data on the modulation of cosmic ray electrons are compared with IMP-8 spacecraft data on low energy He atoms to evaluate the effects of solar maxima on cosmic ray modulation. The investigation is constrained to the modulation of 70-95 MeV He-4 nuclei and 600-1000 MeV electrons over the period 1965-1984, an interval covering solar maxima in 1970 and 1981. It is shown that the occurrences of solar maxima are associated with magnetic field polarity reversals. When the interplanetary magnetic field reverses polarity, oppositely charged particles flow in different directions, thereby permitting studies of drift effects and modulation. Data on the recovery periods after the solar maxima show that the He-4 nuclei recovered before the electron population in 1970, while the situation was reversed in 1981. Actual flux ratio reversals were recorded in the years surrounding the maxima. Although the data support a connection between modulation of cosmic rays and the sign of charged particles, current models cannot account for the deviation of electron intensities from the nuclei intensities.