  Cosmic-ray anti-nuclei provide a promising discovery channel for the indirect
detection of particle dark matter. Hadron showers produced by the
pair-annihilation or decay of Galactic dark matter generate anti-nucleons which
can in turn form light anti-nuclei. Previous studies have only focused on the
spectrum and flux of low energy antideuterons which, although very rarely, are
occasionally also produced by cosmic-ray spallation. Heavier elements
($A\geq3$) have instead entirely negligible astrophysical background and a
primary yield from dark matter which could be detectable by future experiments.
Using a Monte Carlo event generator and an event-by-event phase space analysis,
we compute, for the first time, the production spectrum of \antihe and \antiT
for dark matter annihilating or decaying to $b\bar{b}$ and ${W^+}{W^-}$ final
states. We then employ a semi-analytic model of interstellar and heliospheric
propagation to calculate the \antihe flux as well as to provide tools to relate
the anti-helium spectrum corresponding to an arbitrary antideuteron spectrum.
Finally, we discuss prospects for current and future experiments, including
GAPS and AMS-02.
