  In this paper we report a study of the isotopic composition of Li, Be, B and
N, Ne nuclei from a 5 year time period beyond the heliopause using the CRS
instruments on Voyager. By comparing the isotopic ratios, 15N/14N and 22Ne/20Ne
outside the heliosphere as measured at Voyager, and which are found to be
significantly lower than those measured at the same energy inside the
heliosphere, we have provided strong evidence that cosmic rays of this energy
have lost as much as 200 MeV/nuc or more in the solar modulation process. This
is in accordance with the so called force field description of this overall
modulation by Gleeson and Axford. The measurements at Voyager confirm that the
unusual 14N and 22Ne cosmic ray source abundances relative to solar abundances
made earlier inside the heliosphere extend to the lower energies not accessible
from near Earth measurements. The low energy Li, Be and B nuclei, which are
believed to be purely secondary nuclei, are found to have a (previously
unobservable) peak in the differential intensity spectrum at ~100 MeV/nuc. This
is in agreement with propagation predictions. The intensities of these nuclei
are ~10-20% higher than those predicted in a propagation model with a matter
path length lambda = 9 g/cm2 at these low energies. The isotopic composition of
Li, Be and B nuclei is also consistent with that expected from propagation
through interstellar matter.
