Fusion energy is the process of combining two or more atomic nuclei to form a single, heavier nucleus. It is an alternative to fission energy, which is the process of splitting a nucleus into smaller pieces. Fusion occurs naturally in stars, and scientists are working on ways to replicate it here on Earth.
The advantage of fusion over fission is that it produces much less radioactive waste. In addition, fusion reactors can theoretically produce far more energy than fission reactors. The challenge lies in containing the plasma—the hot, charged gas that results from the fusion reaction—long enough for it to release its energy before cooling off and dissipating.
There are several approaches to achieving this goal, including magnetic confinement, where powerful magnets are used to keep the plasma contained; inertial confinement, where laser beams or particle beams are used to heat and compress the target material; and direct drive, where the target material is placed in close proximity to the power source so that no extra equipment is needed to confine the plasma.
Scientists around the world are working on all three of these approaches in an effort to make fusion power a reality. If successful, fusion could provide a clean and limitless source of energy for generations to come.