The possible sources of light nuclei populations observed recently below th
e geomagnetic cutoff by the AMS experiment are discussed in terms of nuclea
r Processes: fragmentation of the incoming flux of cosmic He-4 on atmospher
ic nuclei, and nuclear coalescence from proton and He-4 induced reactions.
Results of simulations for H-2,H-3 and He-3,He-4, are presented and compare
d to the data. (C) 2001 Elsevier Science B.V. All rights reserved.