A Breakthrough in Fusion Research

When the UW team succeeded in generating plasma, it marked the first step in a new age of fusion research at the university. Bryce Richter

A fusion device at UW–Madison generated plasma for the first time, opening the door to making the highly anticipated, carbon-free energy source a reality.

Over the past four years, a team of UW–Madison physicists and engineers has been constructing and testing the fusion energy device, known as WHAM, in the UW’s Physical Sciences Lab. It transitioned to operations mode last summer, marking a major milestone for the yearslong research project.

“The outlook for decarbonizing our energy sector is just much higher with fusion than anything else,” says Cary Forest ’86, a UW–Madison physics professor who has helped lead the development of WHAM. “[Generating] plasma is a crucial first step for us in that direction.”

Fusion is a type of nuclear energy that produces relatively harmless, carbonless waste products, making it one of the cleanest potential energy sources in terms of greenhouse gases.

“We think fusion will be as good at producing electricity as any energy source would be, and we think it might be even better to use it as a source of industrial heat for making things,” Forest says.

Fusion occurs naturally in our sun and other stars to create heat and energy. Researchers have tried to replicate this process with fusion devices known as mirror machines, which limit the escape of particles from the main reactor with inward-facing magnets. But an inability to efficiently contain the plasma — and therefore to achieve net-positive energy production — had greatly limited the function of the machines until recently. Over the last decade, scientists have developed high-temperature superconductor magnets that are tens of times stronger than the magnets previously used for fusion research.

With these powerful magnets, the UW–Madison team is revisiting mirror machines as plasma energy reactors. When they succeeded in generating plasma, it marked the first step in a new age of fusion research at the university.

Published in the Winter 2024 issue