Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published 1973 | Published
Journal Article Open

Observations of Low Energy Hydrogen and Helium Isotopes during Solar Quiet Times


We report a new quiet-time measurement of the relative abundance of cosmic-ray ^2H and ^4He. The observations were made in selected time intervals between September 1972 and February 1973 with the Caltech Electron/Isotope Spectrometer on IMP-7. In the energy interval 13-29 MeV/nucleon, we find an upper limit to the ^2H to ^4He ratio of Γ(^2H/^4He)< 0.06. This new upper limit is significantly lower than finite ^2H/^4He ratios measured in earlier years by other workers. Possible implications of this new result are discussed.

Additional Information

© 1973 University of Colorado. Provided by the NASA Astrophysics Data System. This work was supported in part by NASA under contract NAS5-11066 and Grant 05-002-160. One of us (Hurford) received support from the National Research Council of Canada while another (Stone) was an Alfred P. Sloan research fellow during this period. Space Radiation Laboratory SRL ID #: 1973-05

Attached Files

Published - 1973-05.pdf


Files (746.7 kB)
Name Size Download all
746.7 kB Preview Download

Additional details

August 19, 2023
October 26, 2023