The Coulomb barrier refers to the electrostatic repulsion between the positively charged nuclei that must be overcome for nuclear fusion to occur.
Why It Matters:
Atomic nuclei are made of positively charged protons, and like charges repel each other due to the Coulomb force. When two nuclei approach each other, this repulsion forms an energy barrier—the Coulomb barrier—that must be overcome for them to get close enough for the strong nuclear force to bind them together in a fusion reaction.
Overcoming the Barrier:
- At high temperatures, nuclei move fast enough to collide with sufficient energy to overcome the barrier.
- In fusion reactors, millions of degrees are required to give particles enough kinetic energy.
- Alternatively, quantum tunneling allows particles to “tunnel through” the barrier even if they don’t have enough energy classically, making fusion possible at slightly lower energies.