A Caltech Library Service

The Elemental Abundance Ratios of Interstellar Secondary and Primary Cosmic Rays

Brown, J. W. and Stone, E. C. and Vogt, R. E. (1973) The Elemental Abundance Ratios of Interstellar Secondary and Primary Cosmic Rays. In: Proceedings of the 13th International Cosmic Ray Conference. Colorado Associated University Press , Denver, CO, pp. 556-561.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The rigidity dependence of the ratios. of abundances of interstellar secondary and primary cosmic rays contains important information on their confinement and propagation in the Galaxy. Recent results suggest that high energy cosmic rays (> 20 GeV/nucleon) have propagated through much less interstellar matter than lower energy nuclei (< 1 GeV/nucleon). We report new observations of abundances in the charge range 2 ≤ Z ≤ 10, which were obtained with a dE/dx-Cerenkov detector launched into a polar orbit on OGO-6 as part of the Caltech Solar and Galactic Cosmic Ray Experiment. Integral rigidity spectra of all the elements observed have shapes similar to that of the helium spectrum in the rigidity range ~ 2 to ~ 14 GV, approaching a power law with exponent -1.6 above 8 GV. Calculations of interstellar propagation assuming a steady-state model and including the presence of interstellar helium and the effects of solar modulation predict a variation with rigidity of ratios such as Be/O and B/O, which is not observed. The data can be explained by assuming a rigidity-dependent confinement of cosmic rays within the Galaxy.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Stone, E. C.0000-0002-2010-5462
Contact Email
Additional Information:© 1973 University of Colorado. Provided by the NASA Astrophysics Data System. Dr. S. S. Murray made significant contributions to the OGO-6 program. Dr. J. Audouze kindly provided us with a copy of the computer program for the propagation calculation and provided us with cross section data. Dr. M. Shea kindly supplied us with detailed geomagnetic cutoff data, and Dr. T. L. Garrard supplied the solar modulation program. We appreciate discussions with Dr. C. Cesarsky. One of us (Brown) received support from the National Science Foundation, while another (Stone) was an Alfred P. Sloan research fellow. This work was supported in part by NASA contract NAS5-9312 and grant NGR 05-002-160. Space Radiation Laboratory SRL ID #: 1973-07.
Group:Space Radiation Laboratory
Funding AgencyGrant Number
NASANGR 05-002-160
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Space Radiation Laboratory1973-07
Record Number:CaltechAUTHORS:20140409-090240805
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:44807
Deposited By: SWORD User
Deposited On:10 Apr 2014 20:46
Last Modified:20 Feb 2020 14:33

Repository Staff Only: item control page