Relativistic interaction of {sup 22}Ne and {sup 26}Mg in hydrogen and the cosmic-ray implications
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)
- Dipartimento di Fisica, Universita di Catania and Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Corso Italia 57, I95129-Catania (Italy)
- Space Science Laboratory, University of California, Berkeley, California 94720 (United States)
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota, 55455 (United States)
- Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)
- NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)
- Service dAstrophysique, Centre dEtudes de Saclay, 91191 Gif-sur-Yvette, Cedex (France)
- Department of Astronomy, New Mexico State University, Las Cruces, (United States)
The isotopic production cross sections for {sup 22}Ne projectiles at 377,581, and 894 MeV nucleon{sup {minus}1} and {sup 26}Mg projectiles at 371 and 576 MeV nucleon{sup {minus}1} interacting in a liquid hydrogen target have been measured by the Transport Collaboration at the Lawrence Berkeley Laboratory Heavy-Ion Spectrometer System (LBL HISS) facility. These cross sections are compared with those predicted by semi-empirical formulae. The systematics are studied to develop suitable inputs for calculations of galactic cosmic-ray interstellar transport. These calculations are used to unfold the transport effects from available observations of cosmic-ray CNO isotopes to extract the underlying source composition. With these new cross section measurements, the previously reported enhancement of {sup 18}O at the cosmic-ray source, which is sensitive to the cross sections for production from {sup 22}Ne and {sup 26}Mg and the uncertainties in cross section prediction formulae, may be explained. There is no evidence for an enhancement of {sup 18}O when these new cross sections are used in a weighted slab propagation calculation. {copyright} {ital 1997} {ital The American Astronomical Society}
- OSTI ID:
- 628684
- Journal Information:
- Astrophysical Journal, Vol. 479, Issue 1; Other Information: PBD: Apr 1997
- Country of Publication:
- United States
- Language:
- English
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