  The waves generated by high-energy proton and alpha particles streaming from
solar flares into regions of colder plasma are explored using particle-in-cell
simulations. Initial distribution functions for the protons and alphas consist
of two populations: an energetic, streaming population represented by an
anisotropic ($T_{\parallel} > T_{\perp}$), one-sided kappa function and a cold,
Maxwellian background population. The anisotropies and non-zero heat fluxes of
these distributions destabilize oblique waves with a range of frequencies below
the proton cyclotron frequency. These waves scatter particles out of the tails
of the initial distributions along constant energy surfaces in the wave frame.
Overlap of the nonlinear resonance widths allows particles to scatter into near
isotropic distributions by the end of the simulations. The dynamics of $^3$He
are explored using test particles. Their temperatures can increase by a factor
of nearly 20. Propagation of such waves into regions above and below the flare
site can lead to heating and transport of $^3$He into the flare acceleration
region. The amount of heated $^3$He that will be driven into the flare site is
proportional to the wave energy. Using values from our simulations, we show
that the abundance of $^3$He driven into the acceleration region should
approach that of $^4$He in the corona. Therefore, waves driven by energetic
ions produced in flares are a strong candidate to drive the enhancements of
$^3$He observed in impulsive flares.
