The rates are calculated for thermonuclear reactions involving the collision of a proton with various light nuclei. These calculations are based directly on low-energy experiments for deuterium, Li, Be, and B, partly on experiments for ${\mathrm{O}}^{16}$, and purely on theoretical estimates for the other isotopes of O, F, Ne, and Na.

Temperatures are calculated at which D, Li, Be, and B are effectively destroyed by these reactions, both in the interior of young and cool stars which are still contracting gravitationally and in the outer layers of main sequence stars. It is shown that in the interior of even a hot main sequence star only ${\mathrm{O}}^{18}$ and ${\mathrm{F}}^{19}$ (and possibly ${\mathrm{O}}^{17}$) are destroyed of all the isotopes heavier than nitrogen.

• Received 11 October 1954

DOI:https://doi.org/10.1103/PhysRev.97.1237