secondary electrons in polymers (references found)

I raised the question a half year earlier or so about how far secondary
electrons could travel in polymers. This week I happened upon a
reference which suggests that it could be in the 100 nm range, since
polymers are insulators:
J. Appl. Phys. 85, 1137 (1999).
Likewise this reference tells how electrons with energies as low as 12
eV can still go through 50 nm of the polymer resist (SAL-601).
J. Vac. Sci. & Tech. B 10, 2877 (1992).
Thanks to earlier respondents for helpful suggestions.
FC