  Studies on Voyager 1 using the CRS instrument have shown the presence of
sub-MeV electrons in the interstellar medium beyond the heliopause. We believe
that these electrons are the very low energy tail of the distribution of
galactic GeV cosmic ray electrons produced in the galaxy. If so this
observation places constraints on the origin and possible source distribution
of these electrons in the galaxy. The intensities of these electrons as well as
MeV protons and other higher energy electrons and nuclei have been followed
outward from the Earth to beyond the heliopause during the 40 years of the
Voyager mission. Among the other new features found in this study of the radial
dependence of the electron intensity in the heliosphere are: 1. The heliosheath
is a source of sub-MeV electrons as well as the already known anomalous cosmic
rays of MeV and above, none of which appear to escape from the heliosphere
because of an almost impenetrable heliopause at these lower energies; 2. Solar
modulation effects are observed for these MeV electrons throughout the
heliosphere. These modulation effects are particularly strong for electrons in
the heliosheath and comprise over 90 percent of the observed intensity change
of these electrons of 10-60 MeV between the Earth and the heliopause. Even for
nuclei of 1 GV in rigidity, over 30 percent of the total intensity difference
between the Earth and the LIM occurs in the heliosheath; 3. The 2 MeV protons
studied here for the first time beyond the heliopause are also part of the low
energy tail of the spectrum of galactic cosmic ray protons, similar to the tail
noted above for sub MeV galactic cosmic ray electrons.
