He-3 in galactic cosmic rays

Journal Article · Mon Dec 01 04:00:00 EST 1986 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/164835· OSTI ID:6447925

Mewaldt, R A

Cosmic-ray He-3/He-4 observations, including a new measurement around 65 MeV per nucleon from ISEE-3, are compared with interstellar propagation and solar modulation calculations in an effort to understand the origin of cosmic-ray He nuclei. A survey of spacecraft and balloon observations of the He-3/He-4 ratio shows improved consistency among measurements in the 50-300 MeV per nucleon energy range when a previously neglected contribution from atmospheric secondary He-3 is taken into account. These low-energy observations imply a mean escape length of 6-8 g/sq cm in the standard leaky box model for cosmic-ray propagation in the Galaxy, a value consistent with that derived from studies of heavier nuclei. No evidence is found for an excess of low-energy He-3 such as that reported at high energies. 42 references.

• Research Organization: California Institute of Technology, Pasadena
• OSTI ID: 6447925
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 311; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
COMPARATIVE EVALUATIONS
COSMIC NUCLEI
COSMIC RADIATION
COSMIC RAY PROPAGATION
ENERGY RANGE
HELIUM ISOTOPES
IONIZING RADIATIONS
ISOTOPE RATIO
ISOTOPES
MEV RANGE
MEV RANGE 10-100
MEV RANGE 100-1000
NUCLEI
ORIGIN
RADIATIONS