Reaction between twoLi6at rest to give threeαparticles

For ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ beam energies of 2 MeV, $\alpha -\alpha$ coincidence measurements show a large, narrow peak due to the direct reaction $2{}_{}{}^6{}_{}{}^{}\mathrm{Li}\to 3\alpha$, where both ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ nuclei contribute one deuteron to make the third $\alpha$ particle. The large volume of three-body phase space allows the various parts of the reaction process to be separated from each other. Excellent fits to the data were obtained using a three-body, extended-range, distorted-wave Born-approximation model. Elastic scattering potentials for the calculation were generated by the double-folding technique in combination with ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ + ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ elastic scattering measurements for ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ beam energies from 2 to 5.5 MeV.