Potential barrier of atomic nucleus

The potential barrier of the atomic nucleus is the energy barrier created by electrostatic repulsion that a positively charged particle must overcome in order to approach the nucleus.

Atomic nucleus held together by attractive forces

The nucleons in the nucleus are held together by the attractive forces of the strong nuclear interaction. These forces decrease rapidly with increasing distance, unlike repulsive forces, which decrease according to Coulomb’s law; as a result, we can consider the nucleus to be stable over time.

If a positively charged particle moves toward the nucleus, it must overcome the electromagnetic repulsive forces, i.e., the potential barrier. The potential of the repulsive forces increases with decreasing distance up to the effective radius of the nucleus, R, at which point the attractive forces begin to dominate, pulling the particle into the nucleus. The potential of the nucleus is greatest at its surface, which corresponds to the effective radius of the nucleus.

The potential barrier prevents thermonuclear reactions from occurring in the plasma. This is because, even at temperatures in the thousands of kelvins, the kinetic energy of the colliding nuclei is lower than their potential barrier. As a result, the nuclei cannot come close enough to each other, and nuclear fusion the formation of a composite nucleus and the release of binding energy cannot occur.

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Wikiskripta - Energie vazby atomového jádra, potenciální bariéra, hmotnostní defekt