
Accession Number : AD0614100
Title : AN INTERPLANETARY DIFFUSION MODEL FOR THE TIME BEHAVIOR OF INTENSITY IN A SOLAR COSMIC RAY EVENT,
Corporate Author : IOWA STATE UNIV IOWA CITY
Personal Author(s) : Krimigis,S. M.
Report Date : 01 APR 1965
Pagination or Media Count : 63
Abstract : It is found possible to give a coherent interpretation of the time history of the intensity of several solar cosmic ray events in terms of a unified interplanetary diffusion model which assumes that the diffusion coeffieient D = M r to the B power, where r is the heliocentric radial distance and M and B are parameters, which may be dependent on particle energy E. The model is particularly successful in accounting for the decay phases. For the September 28, 1961 event M varies as E to the 0.33 power and, assuming spherical geometry, B is equal to one for 55 < E < 500 MeV and decreases rapidly at lower energies. At r = 1 A.U. the mean free path lambda is about 0.081 A.U. for E = 200 MeV and 0.15 for E = 23 MeV. The energy dependences of B and lambda suggest 0.006 A.U. as the order of magnitude of the scale size of irregularities in the interplanetary magnetic field. The source spectrum is inferred. The possibility of nonspherical geometry of diffusion is considered, as is the implication of the results with respect to the solar modulation of galactic cosmic radiation. (Author)
Descriptors : (*COSMIC RAYS, DIFFUSION), (*SOLAR RADIATION, COSMIC RAYS), MATHEMATICAL MODELS, MAGNETIC FIELDS, PLANETS, PROTONS, PARTICLE TRAJECTORIES, SCATTERING, NUMERICAL METHODS AND PROCEDURES, FOURIER ANALYSIS
Distribution Statement : APPROVED FOR PUBLIC RELEASE