  Observations of energetic neutral atoms (ENAs) allow for remote sensing of
plasma properties in distant regions of the heliosphere. So far, most of the
observations have concerned only hydrogen atoms. In this paper, we present
perspectives for observations of helium energetic neutral atoms (He ENAs). We
calculated the expected intensities of He ENAs created by the neutralization of
helium ions in the inner heliosheath and through the secondary ENA mechanism in
the outer heliosheath. We found that the dominant source region for He ENAs is
the inner heliosheath. The obtained magnitudes of intensity spectra suggest
that He ENAs can be observed with future ENA detectors, as those planned on
Interstellar Mapping and Acceleration Probe. Observing He ENAs is most likely
for energies from a few to a few tens of keV/nuc. Estimates of the expected
count rates show that the ratio of helium to hydrogen atoms registered in the
detectors can be as low as 1:10^4. Consequently, the detectors need to be
equipped with an appropriate mass spectrometer capability, allowing for
recognition of chemical elements. Due to the long mean free paths of helium
ions in the inner heliosheath, He ENAs are produced also in the distant
heliospheric tail. This implies that observations of He ENAs can resolve its
structure, which seems challenging from observations of hydrogen ENAs since
energetic protons are neutralized before they progress deeper in the
heliospheric tail.
