Francesco Volpe | Working Towards Net Fusion Energy

Francesco Volpe
Assistant Professor of Applied Physics
This profile is included in the publication Excellentia, which features current research of Columbia Engineering faculty members.

—Photo by Eileen Barroso

For years, scientists and engineers have been working on a way to control nuclear fusion to provide power. They have been experimenting with plasma at a super high temperature in machines called tokamaks. The fuel used is extracted from water and rocks and while the reaction that takes place in the tokamaks is nuclear, no radioactive waste is produced. Still, challenges remain in fusion energy and many scientists are tackling various aspects to make it work, including Francesco Volpe, assistant professor of applied physics.
Volpe is part of a team of researchers at Columbia Engineering who specializes in fusion energy. He focuses on two key aspects: the first is to keep the plasma sufficiently hot for the ions to fuse (and thus liberate energy) in spite of their Coulomb repulsion. The second is to keep the plasma in a high-pressure state (yielding high fusion power) and prevent it from degenerating to reduced pressure or, worse, be destroyed, which while not dangerous for people, can damage the tokamak device. Volpe uses microwaves for both purposes, combined in the second case with magnetic fields. Surprisingly, the underlying mechanisms of these techniques are not very different from the principles by which a microwave oven heats water, and a compass can be steered by a magnet.
“We know the production of energy works but it needs to be optimized,” said Volpe. “One of the challenges is that structures called magnetic islands tend to develop in the plasma, which decrease fusion performances, in several cases so much so that the plasma is destroyed.”
One way to tackle this problem is to suppress magnetic islands as soon as they form by means of microwaves and magnetic fields. Researchers have found, he explained, that the efficiency of the tokamak depends on its size and that a bigger machine is more efficient at producing fusion energy.
Volpe has actually already been involved in a much bigger version of the tokamak in a major international project called ITER—the first of all fusion experiments that will produce net energy. The machine is under construction in France and expected to be completed by 2020. Volpe helped design a launcher of microwaves being used in ITER that suppresses the magnetic islands and assists in keeping the plasma stable.
Even as a young child, Volpe knew he wanted to pursue physics or engineering and “do something useful for the environment.” His fascination with fusion began when he read a book about it at age 16. His interest grew after attending an exhibition on energy and watching a documentary about a tokamak in England.
Volpe joined Columbia in January of 2012 from the University of Wisconsin where he was an assistant professor of engineering physics. He did his postdoc at General Atomics in San Diego, Calif., and worked on DIII-D, another major fusion energy program.
Volpe’s keen interest in fusion has not waned. “It brings together electromagnetism, kinetic physics, optics, materials science, computer simulations and more. So even just as a scientific problem, it is extremely interesting,” said Volpe. “Plus, fusion is useful. We need to do something about the generation of energy and for our environment. Fusion, at least on paper, is perfect. It is difficult to realize, but we’re getting there.”
Laurea, University of Pisa (Italy), 1998; Ph.D., University of Greifswald (Germany), 2003
-Melanie A. Farmer
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