As we scour and scorch the Earth for deeper wells of energy, investors and government agencies are pouring billions into nuclear fusion research. The hope is that fusion may ultimately provide a virtually limitless source of clean energy.
And there's reason to hope.
Fusion powers the stars, including our sun, and scientists have recently shown that it's feasible to replicate this reaction here on Earth.
But there are some real head-scratchers between us and actually containing a miniature burning star heart on our precious, fragile planet.
A crucial step toward achieving this goal is to simulate it.
Researchers like Virginia Tech mathematician Ionut Farcas are using sophisticated computational models to troubleshoot fusion reactors before we build them.
"In a real fusion power plant, the control algorithms have to be bulletproof," Farcas said. "There is no room for error."
Too hot to handle
One major engineering challenge is determining the right materials to sustain the unbelievably high temperatures required for fusion.
The core of the sun consists of an extremely hot, electrically charged gas called plasma with temperatures of roughly 27 million degrees Fahrenheit. The sun's immense gravity produces pressures in the core reaching hundreds of billions of times Earth's atmospheric pressure.
But fusion reactors on Earth cannot rely on the Sun's immense gravitational pressure, so they must operate at even higher temperatures — exceeding 180 million degrees Fahrenheit.
"There is no known material on Earth that can contain plasma at those temperatures," Farcas said.
So instead, researchers leverage the fact that plasma is a hot soup of charged particles that can be kept suspended in a magnetic field — like Magneto from the superhero series the X-Men, who was isolated in a specialized prison designed to contain his power.
Too cool to fuel
Even at such high temperatures, turbulence within the plasma can cause heat loss, preventing the plasma from sustaining the conditions needed for nuclear fusion.
"We need materials and the control strategies that can sustain high temperatures and heavy operational loads," Farcas said.
The upper limit of complicated
Computational models are essential for understanding the complex processes behind plasma physics and will enable scientists to design, build, control, and ultimately operate nuclear fusion devices, Farcas said.
But we're talking about physics in the most extreme conditions, which can change quickly — sometimes abruptly. Modeling a single plasma control problem might require a supercomputer to run for days or even weeks; not ideal for real-time control and decision making.
Computers are essential for performing these types of computations, but it can still take a cost-prohibitively long time to reach an answer that can be validated against experimental data.
Farcas developed a way to run these computations faster with something called a reduced model.
The technique captures the salient features of a problem by sacrificing some detail to compress days of computation into seconds or less and thereby paving the way for real-time prediction, design, control, and decision making.
He demonstrated how reduced modeling can lay the groundwork for real-time plasma control in a recent paper in the Physics of Plasma , a study in the Journal of Computational Physics , and an article in The Bridge magazine from the National Academy of Engineering .
Reduced models are application agnostic: Farcas and collaborators explored how they can be plugged into simulating next-generation rocket engines in a paper published in Nature Chemical Engineering .
"Best-case scenario for realistic rocket simulation usually takes about three days of computation for a mere millisecond of physical time," Farcas said. "Our reduced model gave the answer in one second."
Reduced models can be applied in any field, which is good because nuclear fusion is interdisciplinary by nature.
"It's not just a physics problem, or an engineering problem, or a math problem," Farcas said. "The solution doesn't belong to a single field either but rather has to be an interdisciplinary effort."
Original study DOI:10.1063/5.0311057
Original study DOI: 10.1016/j.jcp.2026.114718
Original study DOI: 10.1038/s44286-026-00377-0
