Part 4/10:
At the heart of fusion is the process of combining light atomic nuclei to form heavier ones, releasing vast amounts of energy in the process. This is the same reaction that powers the Sun and other stars. In a fusion reactor, the goal is to bring together light elements like hydrogen or its isotopes, deuterium and tritium, and fuse them into helium, releasing energy.
The challenge lies in overcoming the electrostatic repulsion between the positively charged nuclei, which want to push each other apart. To achieve fusion, the nuclei must be heated to extremely high temperatures, allowing them to overcome this "Coulomb barrier" and collide with sufficient force to fuse.