It is only a weak function of energy for the low energies relevant to these studies. $R_{\mathrm{IS}}(T_{\mathrm{IS}})$ and $R_{\mathrm{solar}}(T_{\mathrm{IS}})$ are interstellar propagation ratios and the shifted solar ratios shown in Fig. \[fig:propagation\]. This expression allows one to easily take more detailed analyses of [$\overline{\text{D}}~$]{}spectra, rates or counts (as found in, for example, Refs. [@ibarra2013; @fornengo2013]) and scale them to the [$^3\overline{\text{He}}~$]{}case, as well as incorporate new coalescence momentum measurements when they become available.

We then compute the flux at the top of Earth’s atmosphere for a set of benchmark cases using the same dark matter models we considered in Sec. \[sec:production\] and the propagation setup described in Sec. \[sec:propagation\]. In particular, we adopt $p_0^{A=2}=0.192, p_0^{A=3}=0.357$, MED propagation parameters, and use the slightly more optimistic “MethodANN” value for the antihelium interaction cross-section with the ISM.

In Figure \[fig:flux\] we present the flux at the top of the Earth’s atmosphere for dark matter annihilating to $W^+W^-$ and $b\bar{b}$ final states with a thermally-averaged pair annihilation cross section $\langle\sigma v\rangle=3\times10^{-26}\ {\rm cm}^3/{\rm s}$ as well as propagation uncertainties. Also shown are the latest sensitivities for AMS-02, GAPS(LDB/LDB+) [@snowmass2013] and a GAPS(SAT) mission as proposed in Ref. [@GAPS_first]. We note that the propagation uncertainties 