High-Resolution, Low-Energy Dissociative Recombination Spectrum ofHe3H+

We report the first high-resolution cross section measurements of dissociative recombination in ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ ${\mathrm{H}}^{+}$ for $0.05 \mathrm{meV}\le E_{\mathrm{rel}}\le 300 \mathrm{meV}$. We used the electron cooling beam of the storage ring CRYRING, which now features $k{T}_{\perp }\sim 10$ meV. The experiment confirms the puzzlingly large lowenergy rate measured previously and finds six heretofore unreported peaks at 34, 54, 113, 216, 250, and 284 meV. We remark on the utility of the Fourier transform to remove peak shifts and broadening due to the electron beam's thermal energy spread.