Gamow factor
= Gamow factor
{c}
{title2=$e^{-2\pi\eta}$}
The semiclassical penetration factor for two repelling point charges is approximately $\exp(-2\pi\eta)$, where $\eta=Z_1Z_2\alpha_{\rm fs}\sqrt{\mu c^2/(2E)}$. It represents the long-range Coulomb suppression, not the <nuclear reaction> probability after penetration.