  A method is reported for a simple, yet reliable, calculation of electron
inelastic mean free paths in condensed phase insulating and conducting
materials, from the very low energies of hot electrons up to the high energies
characteristic of electron beams. Through a detailed consideration of the
energy transferred by the projectile in individual and collective electronic
excitations, as well as ionizations, together with the inclusion of higher
order corrections to the results provided by the dielectric formalism,
inelastic mean free paths are calculated for water, aluminum, gold and copper
in excellent agreement with the available experimental data, even at the
elusive very low energy region. These results are important due to the crucial
role played by low energy electrons in radiobiology (owing to their relevant
effects in biodamage), and also in order to assess the not yet elucidated
disagreement between older and recent measurements of low energy electron mean
free paths in metals (which are relevant for low energy electron transport and
effects in nanostructured devices).
