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

Journal Article · Sat Mar 01 00:00:00 EST 1986 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA091iA03p02858· OSTI ID:5875596

Garcia-Munoz, M; Meyer, P; Pyle, K R; Simpson, J A; Evenson, P

We compare the solar modulation of galactic cosmic ray helium and electrons at 1 AU, within the 600- to 1000-MV magnetic rigidity interval, during a period covering 20 years, from the solar minimum of 1965 through 1984. Most of the data were obtained by University of Chicago cosmic ray telescopes on board balloons and the IMP series and ISEE 3 satellites. Comparison of the time-intensity variations during the two solar maxima around 1970 and 1981 shows that after 1970 the intensity of helium recovers earlier than that of the electrons, whereas after 1981 the intensity of electrons recovers earlier than that of helium. Within the measured magnetic rigidity interval the flux ratio of helium to electrons (He/e) undergoes a major increase during 1969-1971 and a major decrease during 1979-1983, periods that include the times of reversal of the polarity of the solar polar magnetic fields. A conventional model of solar modulation can describe the modulation of protons and helium from 1965 through 1984, but its predictions depart significantly from the observed modulation of electrons around and after the 1981 solar maximum. The difference in particle velocity between nuclei and electrons in the rigidity interval under study cannot alone account for the observations. The above experimental findings are consistent with a dependence of the solar modulation of galactic cosmic rays on the sign of the particle charge.

• Research Organization: Enrico Fermi Institute, University of Chicago, Illinois
• OSTI ID: 5875596
• Journal Information: J. Geophys. Res.; (United States), Vol. 91:A3
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COSMIC RADIATION
MODULATION
CHARGED PARTICLES
COSMIC ELECTRONS
COSMIC RAY FLUX
HELIUM
INTERPLANETARY MAGNETIC FIELDS
SATELLITES
SOLAR CYCLE
TELESCOPES
ELECTRONS
ELEMENTARY PARTICLES
ELEMENTS
FERMIONS
FLUIDS
GASES
IONIZING RADIATIONS
LEPTONS
MAGNETIC FIELDS
NONMETALS
RADIATION FLUX
RADIATIONS
RARE GASES
640101* - Astrophysics & Cosmology- Cosmic Radiation