Accession Number:

AD0775862

Title:

Anomalous Cosmic-Ray Anisotropy and Unidirectional Interplanetary Magnetic Field during 1954,

Descriptive Note:

Corporate Author:

STANFORD UNIV CALIF INST FOR PLASMA RESEARCH

Personal Author(s):

Report Date:

1973-09-01

Pagination or Media Count:

20.0

Abstract:

Observations of the interplanetary magnetic field during solar minimum lead to the following important conclusions for cosmic ray modulation a the interplanetary magnetic field does not show any sector structure for a few solar rotations, i.e. the field has polarity away from the sun during this interval, b cosmic ray diffusion in the interplanetary medium is essentially anisotropic for rigidity of the order of 10 GV K parallelK perpendicular approximately 0.01 ratio of diffusion coefficients calculated from the magnetic-field power spectra by Jokipii and Coleman. If diffusion occurs essentially along the magnetic field lines, the cosmic ray density Ur, T is a symmetric function of the heliolatitude lambda with a minimum in the equatorial plane Ur, T, lambda proportional to a exp-b cosine squared lambda. Therefore a cosmic ray density gradient across the solar equatorial plane exists and it depends on the size of the modulation region. Modified author abstract

Subject Categories:

  • Astrophysics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE