Gamow Energy, Peak, Width and Window?
The likelihood of a reaction occuring at a given energy is a product of the number of particles with that energy (the Maxwell Boltzmann distribution), which decreases with energy, and the tunneling probability, which increases with energy. This product forms the Gamow window.
The total reaction rate (for a non-resonant reaction) is proportional to the area under the Gamow window - i.e. the product of its width and height.
For resonant reactions, that occur over a narrow energy range, all that really matters is how close to the peak of the Gamow window that energy is.