An excitation curve has been measured for the reaction ${\mathrm{C}}^{12}(p, \gamma ){\mathrm{N}}^{13}$ in the energy interval 80 kev to 126 kev by utilizing beam currents of 30 ma to 50 ma from the high-current ion injector. The capture-gamma radiation was measured with a 4-in.×4-in. NaI scintillator which was arranged to count only gamma radiation of the energy appropriate to the reaction. The yield per incident proton ranges from (7.0±2.3)×${10}^{-18\mathrm{}}$ at 80 kev to (6.2±0.2)×${10}^{-16\mathrm{}}$ at 126 kev with corresponding cross sections of (1.4±0.4)×${10}^{-11\mathrm{}}$ barn and (6.8±0.8)×${10}^{-10\mathrm{}}$ barn. A value for the cross section of the reaction ${\mathrm{C}}^{13}(p, \gamma ){\mathrm{N}}^{14}$ has been obtained at two energies, namely: (8.2±2.5)×${10}^{-9\mathrm{}}$ barn at 126 kev, and (5.1±2.0)×${10}^{-9\mathrm{}}$ barn at 114 kev. The results are compared with previous measurements and with extrapolations from the resonance in this reaction at 456 kev by means of the Breit-Wigner single-level dispersion formula.

• Received 2 April 1957

DOI:https://doi.org/10.1103/PhysRev.107.550