What is Fusion?

Fusion is all around.

Illustration: What is Fusion?
Illustration by Ana Kova for U.S. Fusion Outreach

Fusion energy is fundamental to our universe. Fusion occurs when two atoms combine to form a new atom, releasing vast amounts of energy in the process. Our sun and all the stars in the night sky run on fusion energy, creating the building blocks of life and impacting everything in the world around us.

Unlike in the stars, where immense heat and gravitational pressures sustain fusion reactions for billions of years, creating and controlling fusion reactions on Earth requires extreme pressures and temperatures. Since the first fusion experiments were conducted in the 1930s, scientists have made steady progress in advancing technologies toward a commercial fusion reactor.

Controlling, sustaining, and applying the energy from these reactions is what makes the pursuit of fusion energy one of the most complex scientific challenges in human history. 

After generations of research and development, the scientific community believes it is at the threshold of harnessing the power of fusion to generate electricity, creating a viable path to a nearly-limitless, sustainable energy source.