kernbarrière
Kernbarriere is a term used in nuclear physics to describe the potential energy barrier that two atomic nuclei must overcome or tunnel through in order to engage in a nuclear reaction, most notably fusion. The barrier arises from the electrostatic repulsion between positively charged nuclei (the Coulomb barrier) at larger separations, combined with the short-range attractive nuclear force that binds nucleons when they come within about 1 femtometer.
Qualitatively, at separations greater than roughly 1 fm, the Coulomb repulsion raises the potential energy; only
Reactions occur if the incident energy is sufficient to overcome the barrier or if quantum tunneling allows
Although commonly discussed in the context of fusion, a related concept is the fission barrier, which is