Isotopic composition of cosmic rays with 5 < or =Z < or =26

Journal Article · Sat May 01 04:00:00 EDT 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154349· OSTI ID:7272773

Fisher, A J; Hagen, F A; Maehl, R C; Ormes, J F; Arens, J F

Results obtained from a high-altitude balloon flight from Thompson, Canada, in 1973 August are reported. The instrument consisted of a spark chamber, a Lucite Cerenkov counter, and 13 layers of scintillators. For heavy particles the Cerenkov-range method of analysis is used to determine the mass of particles energetic enough to produce a Cerenkov signal and then stop in the layered scintillators. In the energy range 350 MeV per amu approximately-less-thanT approximately-less-than 600 MeV per amu, it is found that /sup 16/O/O >0.9, /sup 12/C/C>0.9, /sup 14/N/N=0.6 +- 0.2. Additionally we find even-Z elements in the 12 < or =Z< or =16 group to be predominantly ..cap alpha..-particle nuclei. Neon, on the other hand, seems to have a significant component of neutron-rich isotopes. While limited by statistical accuracy in the 17< or =Z< or =25 region, the data appear to be consistent with current cosmic-ray propagation models. Iron is found to be predominantly /sup 56/Fe, with some /sup 54/Fe being evident; the mean atomic mass of iron calculated from these data is 55.4 +- 0.3. Using a simple exponential-path-length propagation model these data are extrapolated to thecosmic-ray source and discuss some implications of the data as to the nature of the source. (AIP)

• Research Organization: NASA/Goddard Space Flight Center
• OSTI ID: 7272773
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 205:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics &amp; Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALI METALS
ALKALINE EARTH METALS
ALUMINIUM
ARGON
BERYLLIUM
BORON
CALCIUM
CARBON
CARBON 12
CARBON 13
CARBON ISOTOPES
CHEMICAL COMPOSITION
CHLORINE
CHROMIUM
COSMIC RAY DETECTION
COSMIC RAY FLUX
COSMIC RAY SOURCES
CRYOGENIC FLUIDS
ELEMENTS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FLUIDS
FLUORINE
HALOGENS
IRON
ISOTOPE RATIO
ISOTOPES
LIGHT NUCLEI
LITHIUM
MAGNESIUM
MANGANESE
METALS
NEON
NITROGEN
NITROGEN 14
NITROGEN 15
NITROGEN ISOTOPES
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
OXYGEN
OXYGEN 16
OXYGEN 17
OXYGEN 18
OXYGEN ISOTOPES
PHOSPHORUS
POTASSIUM
RADIATION DETECTION
RADIATION FLUX
RARE GASES
SCANDIUM
SEMIMETALS
SILICON
SODIUM
STABLE ISOTOPES
SULFUR
TITANIUM
TRANSITION ELEMENTS
VANADIUM