The gamma-ray threshold technique has been used with the ${\mathrm{F}}^{19}(d, n\gamma ){\mathrm{Ne}}^{20}$ reaction to find excited states in the residual nucleus, ${\mathrm{Ne}}^{20}$. Thin targets of Ca${\mathrm{F}}_2$ were bombarded with deuterons from a 2-Mv Van de Graaff accelerator. Two NaI(Tl) crystals (1.75-in.×1.75-in. and 3-in.×3-in.) were used in a coincidence arrangement to measure the gamma rays as a function of deuteron energy. Nine gamma-ray or neutron thresholds were found, at bombarding energies of 0.51±0.02, 0.60±0.02?, 0.76±0.02, 0.85±0.02?, 1.15±0.02, 1.35±0.02, 1.70±0.02, 1.79±0.02, and 2.06±0.02 Mev. These threshold energies correspond to excited states in ${\mathrm{Ne}}^{20}$ at 11.11±0.02, 11.19±0.02?, 11.33±0.02, 11.42±0.02?, 11.69±0.02, 11.87±0.02, 12.19±0.02, 12.27±0.02, and 12.51±0.02 Mev, respectively. All of these states decay principally to the ground state of ${\mathrm{Ne}}^{20}$ except the 11.11-, 11.19-, and 12.27-Mev states, which decay primarily to the 1.63-Mev state. Possible isobaric spin assignments are discussed.

• Received 21 October 1959

DOI:https://doi.org/10.1103/PhysRev.118.222