Evidence for Differences in the Energy Spectra of Cosmic Ray Nuclei

Results on the Energy Dependence of Cosmic-Ray Charge Composition 1.

“…Our result that the B+N spectrum is steeper than the spectrum of C+O is qualitatively consistent with the differences between L and M nuclei previously reported: Webber and Ormes (1967), Smith et al, (1973), andWebber et al, (1973). The data all indicate the spectra of secondary nuclei are steeper than those of primaries in agreement with Smith et al, (1973) and Juliusson et al, (1972).…”

“…We believe (Onrmes andBalasubrahmanyan, 1973, Ramaty et al, 1973) that the difference between the Fe and C+O spectra is too large to be explained as a propagation effect as attempted by Webber et al, (1973).…”

“…If the leakage length does decrease faster than this, i.e. to a few tenths of a gm/an2 by 100 GeV/nucleon (Webber et al, 1973) then there will be severe difficulties with galactic models in -18-explaining the isotropy of underground muons from cosmic rays at 101 2 eV (Elliot et al, 1970, Audouze andCesarsky, 1973).…”

“…Until recently the detailed study of the energy distribution of galactic cosmic rays above 10 GeV/nucleon was confined to integral measurements using threshold devices (von Rosenvinge, 1970,Webber et al, 1973. Current experimental programs of the Berkeley group (Smith et al, 1973), University of Chicago (Juliusson et al, 1972) and Goddard Space Flight Center (Ormes and Balasubrahmanyan, 1970) are attempting to extend the knowledge of charge carposition to approximately 100 GeV/nucleon.…”

Global Dynamics of the Interstellar Gas, Magnetic Field, and Cosmic Rays

“…The most recent measurements (Garcia-Munoz et al 1975;Webber et al 1977) suggest total residence times of the order of 2 χ 10 7 years.…”