Propagation of ultraheavy cosmic rays

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1984

OSTI ID:5704688

Brewster, N R

This thesis uses a mathematical model to analyze the passage, or propagation, of cosmic rays through the interstellar medium. The effects of varying different parameters of the model are studied to determine the sensitivity of predicted cosmic ray abundances to these parameters. The effects of assuming different elemental compositions at the source of the cosmic rays is also investigated. Several abundance ratios are identified as particularly sensitive to either changes in the propagation parameters or to the source composition. As part of the study of the input parameters to the model, an experiment was performed to measure the total and partial charge changing cross sections for a heavy nucleus, in this case /sup 197/Au with an incident energy of 990 MeV/nucleon, an energy comparable to that of the most abundant cosmic rays. Such cross sections are important parameters in cosmic ray propagation models, but very few of them, especially for the heaviest nuclei, have been measured. The experiment reported here provides a check on the validity of these formulas for one of the heaviest nuclei occurring in the cosmic radiation, and adds to the list of cross sections that have actually been measured. Finally, the model was used to interpret cosmic ray abundances measured by an experiment on the HEAO-C3 satellite.

• OSTI ID: 5704688
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CHARGE EXCHANGE
CHARGED-PARTICLE TRANSPORT
CHEMICAL COMPOSITION
COSMIC NUCLEI
COSMIC RADIATION
CROSS SECTIONS
GOLD 197
GOLD ISOTOPES
HEAVY NUCLEI
INTERSTELLAR SPACE
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MEASURING METHODS
NUCLEI
ODD-EVEN NUCLEI
RADIATION TRANSPORT
RADIATIONS
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
SPACE
STABLE ISOTOPES