The effect of a bounded interplanetary diffusion medium on the propagation of solar flare cosmic rays

✍ Scribed by Julius Feit

• Publisher: Springer
• Year: 1971
• Tongue: English
• Weight: 859 KB
• Volume: 17
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00150049

✦ Synopsis

An analysis of solar flare data indicates that the graph of log(ntZ/(2-~)) deviates late in the solar event from the straight line predicted for the infinite, unbounded interplanetary medium. It is shown by mathematical analysis, utilizing a model based on the radial diffusion coefficient D =MRS, with 17 _~ 1, that the deviation can be ascribed to the loss of flare particles through an external boundary at about 5-6 AU from the Sun. An inner region terminating at 5-6 AU, followed by an extensive region of increasingly less resistance to the diffusion of flare particles is also feasible and it is shown that measurements taken at the Earth cannot predict the extent of this outer region. The results are applicable to either the isotropic or highly anisotropic models. The constant diffusion model is shown to be inadequate since it requires a boundary ~< 1.5 AU from the Sun. In view of the present and previous studies of solar flare data, it is asserted that the fundamental principle governing the diffusion of solar flare particles through interplanetary space is the radial diffusion coefficient mode of propagation.