Improved measurements of ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ spectra from the ${}_{}{}^7{}_{}{}^{}\mathrm{Li}(t,{}_{}{}^3{}_{}{}^{}\mathrm{He}){}_{}{}^7{}_{}{}^{}\mathrm{He}$ reaction have given final results for the ${}_{}{}^7{}_{}{}^{}\mathrm{He}$ ground state. The ${}_{}{}^7{}_{}{}^{}\mathrm{He}$ mass excess (${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$=O) and width were determined, respectively, to be 26.11±0.03 and 0.16±0.03 MeV. Measurements of differential cross section for the ground-state group are reported for center-of-mass angles of 11° to 63°, and for a triton bombarding energy of 22.0 MeV.

• Received 9 October 1968

DOI:https://doi.org/10.1103/PhysRev.178.2024