Pair Spectrometer Measurements of the Radiations from Excited States of Light Nuceli

A magnetic-lens pair spectrometer has been used to study the radiations produced by the bombardment of certain light nuclei with protons and deuterons from a Van de Graaff accelerator. Gamma rays from the bombardment of F¹⁹ with 3.7-Mev protons were observed at 6.10±{}0.04 and 6.99±{}0.04 Mev. At 4.7-Mev bombarding energy, no lines were observed between 7.5 and 11.0 Mev with an intensity as great as 10 percent of that of the 6.99-Mev line. Gamma rays from the bombardment of C¹³ with 2.0-Mev deuterons were observed at 3.42±{}0.03, 3.71±{}0.05, 3.94±{}0.06, 4.48±{}0.04, 4.96±{}0.03, 5.12±{}0.04, 5.74±{}0.03, 6.14 ±{}0.03, 6.53±{}0.05, and 6.72±{}0.03 Mev. At 4.0-Mev bombarding energy, lines were observed at 6.14±{}0.03, 6.53±{}0.04, 6.72±{}0.03, 7.09±{}0.03, and 7.34±{}0.04 Mev. Gamma rays from the bombardment of C¹² with 4.0-Mev deuterons were observed at 3.76±{}0.02 and 3.86±{}0.02 Mev. No lines were observed between 3.86 and 5.8 Mev with an intensity as great as 10 percent of that of the 3.86-Mev line. All the energies of γ rays given above are uncorrected for Doppler shifts which in some cases are as large as 40 kev. A search was made for nuclear pairs which might originate from the proton bombardment of B¹¹. No pairs were observed at 4.0-Mev bombarding energy in the energy range between 6.5 and 9.5 Mev. A search was also made for nuclear pairs which might result from the Li⁷(d, n)Be⁸ reaction. No pairs were observed in the energy range between 5.0 and 8.5 Mev.