What Is Fusion?

Check out Fusion 101, a video that explains the basics of fusion and ongoing research at the PSFC.


Stars like our sun are fuled by fusion, which combines light elements like hydrogen to form heavier ones like helium, a process that releases enormous amounts of energy in the form of light and heat.

Scientists at the PSFC are trying to harness fusion energy on earth, with the goal of designing power plants that will emit zero carbon, are safe, and incredibly power dense. Achieving fusion is difficult because it only occurs at extremely high temperatures when matter is in the form of plasma – a superheated, ionized gas. In a star, the enormous pull of gravity heats and confines the hot plasma. We lack that gravity, so instead, scientists use strong magnetic fields or powerful lasers to squeeze charged particles. If researchers succeed, we will be able to draw power from a man-made star for a planet with rapidly growing energy needs.


Why Fusion?

Fusion is the power source of the universe, since it is the process producing energy at the center of all stars, including our own sun. Inside stars temperatures above 10 million degrees allow for the hydrogen, the main constituent of stars, to fuse together to produce another element, helium. Stars can produce fusion energy for billions of years because hydrogen, its fuel, is by far the most abundant element in the universe, and because each fusion process releases staggering amounts of energy, about 10 million times the energy released in standard chemical reactions. It is precisely these features that make fusion so attractive as an energy source here on Earth. The fuels are so abundant in ordinary sea water as to make it effectively inexhaustible. The fusion process requires such high temperatures, and does not rely on a chain reaction, that it is inherently safe because intrusion from the outside world immediately eliminates the possibility of any further fusion. The fusion reaction itself produces no long-lived radioactive products – only helium. But like fission, it can produce large amounts of power in compact, central plants meaning that it can be deployed at a scale that would impact our energy portfolio in a decade timescale.


How is the PSFC contributing?

Making clean and economical fusion energy available to our society is a grand challenge of 21st century science and engineering. The PSFC, along with global research partners, seeks to answer this challenge by exploring innovative ways to accelerate the pace of fusion’s development. The PSFC is an interdisciplinary research center because fusion requires an approach that folds in the majority of the engineering and science disciplines found at MIT: physics, nuclear science and engineering, mechanical engineering, chemistry, and material science, to name a few. Our mission is to identify and understand how cutting-edge advances in science and technology can provide fusion energy “smaller and sooner”. The PSFC hosts a wide variety of experimental facilities at the Albany Street corridor on the campus of MIT including plasma devices, powerful superconductor magnets and high-energy accelerators. In parallel, novel measurements are developed for the very challenging fusion environment, which are then compared to leading-edge theory and simulation. This research mission is completely integrated with the training and mentoring a new generation of multidisciplinary fusion scientists and engineers. All in all this makes the PSFC a vital and important contributor to the fusion energy mission.