A portion of the excitation curve of the thermonuclear reaction ${\mathrm{N}}^{14}(p, \gamma ){\mathrm{O}}^{15}$ has been measured using protons of 100 to 135 kev. The cross section of this reaction ranges from (8.5±3.7)×${10}^{-12\mathrm{}}$ barn at 100 kev to (1.4±0.3)×${10}^{-10\mathrm{}}$ barn at 135 kev. The approximate constant $S_0$ is defined by $S_0=E\sigma \exp \left(31.281\mathrm{}{Z}_p{Z}_n{A}^{\frac{1}{2}}{E}^{-\frac{1}{2}}\right)$, where $E$ is the energy in the center-of-mass system and is measured in kev, $\sigma$ is in barns, $A$ is the reduced mass of the interacting nuclei, and $Z_p$ and $Z_n$ are the nuclear number of protons and nitrogen, respectively. Based upon these measurements, $S_0=2.7\mathrm{}\pm 0.2$ kev-barn.

• Received 12 August 1957

DOI:https://doi.org/10.1103/PhysRev.108.1304