Fusion powers the sun and all the stars in the galaxy. It produces nearly all of the elements. It’s the power inside a thermonuclear weapon. No wonder it has the capacity to captivate the collective imagination—both with hopes and fears—like no other field of science or engineering.
On a sub-atomic level, fusion refers to the smashing together of atomic nuclei to produce energy. Research into fusion for the production of electricity has been a 60-year international pursuit, and harnessing it for the energy grid is one of the 14 grand challenges for engineering in the 21st century.
It’s not that fusion hasn’t been achieved yet. It’s that researchers have not yet figured out how to create it with a net energy gain.
“It’s easy to make a fusion happen if you’re only interested in putting out 1/10,000th of the power out that you are putting in to make it happen,” said Assistant Professor David Donovan. “But a power plant only works if there is greater energy out than energy in.”
He added that this helps give it a clear win or lose view on fusion’s success: Either it worked or it didn’t, and until researchers can cross that threshold, then it hasn’t been achieved.
To produce experiments, fusion research has received vast funding to build devices that can not only produce a reaction, but also be contained in a structure that won’t melt from the intense heat created. This is a major aspect of the focus on fusion research at UT. Donovan says that while plasma gets most of the attention in nuclear engineering research, materials and technology research are essential to making fusion a truly viable energy source.
Unlike a fission reactor, there’s no equivalency of meltdown in a fusion reactor. However, the containment walls of a fusion device need to be able to withstand the hottest known temperatures on the planet, and that requires developing new materials.
Both government and private enterprises have joined the race to achieve a reliable source of fusion energy for the power grid. The largest fusion experiment in the world is a $20 billion international effort located in France with a construction completion date of 2025.
When finished, ITER, which means “The Way” in Latin, could produce fusion on a scale to power the planet. Its donut-shaped Tokamak reactor design is three stories tall and the steel structure containing it is the largest steel structure in the world.
Donovan says that it’s very alluring to say researchers can create this next-generation nuclear reactor simply through computer modeling, but at the end of the day, they still don’t know what they don’t know, and at some point, a reactor just has to be built.
“It’s a financial risk, but we have to build fusion devices to experiment,” he said. “We want to do as much homework as we can ahead of time, but at some point, we have to acknowledge that it’s never going to be perfect. Fission power wasn’t perfect when it began.”
Donovan loves that fusion shows up in the realm of sci-fi because it attracts more people to the field, but he says it’s often perceived as having one secret that needs to be unlocked.
Challenges are understandable, considering fusion devices can have the hottest and coldest temperatures in the universe within a few meters of each other—all of them manmade. However, with a vision that extends far into the future and a population expected to grow by a billion people in the next decade, the value of pursuing fusion energy cannot be underestimated.
Élan Young: firstname.lastname@example.org