We investigate a mechanism to produce a seed population enriched in heavy ions, such as those observed in3He-rich solar energetic particle events. It is shown that if an initial particle population following a power law inenergy nucleon?1 passes through a small amount of material, at energies below the dE/dx Bragg peak, the greateraffinity of heavier ions for electron pick-up results in their penetrating the material more easily. This results in anenhancement of heavy ions in the particle population that just barely penetrates the material. The bulk of the seedparticles fall in the energy range of 10 s of keV nucleon?1. It is supposed that some further process then energizesthis seed population to produce the particles observed in interplanetary space. We find a broad range of parametersthat produces enhancements comparable to Fe/O ～ 8 commonly observed.
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