Secondary electron energy distribution (SEED) from Mo, Ni and Pt was measured in helium ion microscope (HeIM)
with semispherical retarding potential technique. For all investigated metals the energy position of the SEED maximum
and the SEED width in HeIM is found to be noticeably less than in conventional scanning electron microscope and even
less than predicted by previous numerical simulations. A simple analytical phenomenological function to describe the
SEED shape is suggested. The reasons of the lower energy transfer efficiency in ion-electron interaction are discussed.
The impact of the presence of a surface layer on SEED in HeIM is investigated and energy selective images of the
specimen with hydrocarbon contaminated region are presented.