12 research outputs found
Re-evaluation of cosmic ray cutoff terminology
The study of cosmic ray access to locations inside the geomagnetic field has evolved in a manner that has led to some misunderstanding and misapplication of the terminology originally developed to describe particle access. This paper presents what is believed to be a useful set of definitions for cosmic ray cutoff terminology for use in theoretical and experimental cosmic ray studies
Galactic Cosmic Rays from Supernova Remnants (I) - a Cosmic Ray Composition controlled by Volatility and Mass-to-Charge Ratio
This is the first of a series of papers analysing the Galactic Cosmic Ray
composition and origin. We show that the Galactic Cosmic Ray source (GCRS)
composition is best described in terms of (i) a general enhancement of the
refractory elements relative to the volatile ones, and (ii) among the volatile
elements, an enhancement of the heavier elements relative to the lighter ones;
this mass dependence most likely reflects a mass-to-charge (A/Q) dependence of
the acceleration efficiency; among the refractory elements, there is NO such
enhancement of heavier species, or only a much weaker one. We regard as
coincidental the similarity between the GCRS composition and that of the solar
corona, which is biased according to first ionization potential. In a companion
paper, this GCRS composition is interpreted in terms of an acceleration by
supernova shock waves of interstellar and/or circumstellar (eg Ne22 rich
Wolf-Rayet wind) gas-phase and especially dust material.Comment: 23 pages plain TeX and 6 postscript figures, to appear in ApJ, also
available from ftp://wonka.physics.ncsu.edu/pub/elliso
The relative abundances of the elements scandium to manganese in relativistic cosmic rays and the possible radioactive decay of manganese 54
We report measurements of the abundances relative to iron of the elements scandium through manganese in galactic cosmic rays in the energy interval 0.7 to 18 GeV/n using data collected by our cosmic ray telescope on the HEAO-3 satellite. The variation versus energy of the abundance ratio of manganese over iron is markedly flatter than that of other iron secondaries. This difference is interpreted as being due to 54Mn survival at E > 15 GeV/n and to its progressive beta decay at lower energies