Could a magnetic blob percolating at Swarthmore save the world?
No, that’s not the plot of a B-movie, but rather the dream of Mike Brown and his colleagues in the Swarthmore Spheromak Experiment (SSX) lab. They are helping to fuel an international effort to bring boundless, clean energy to Earth.
“It’s a real thrill for us as a small-scale research operation at Swarthmore to be connected to this much bigger, mankind-saving enterprise,” says Brown, professor and department chair of physics and astronomy.
Swarthmore joins teams of scientists from around the U.S. hoping to harpoon the white whale of science: nuclear fusion. The reaction that drives the sun, nuclear fusion could offer energy for all, with none of the gases that stoke global warming. But a method for harnessing it has eluded scientists for decades.
There are two $20-billion projects underway in the hopes of finding one: a laser fusion reactor at the National Ignition Facility (NIF) near San Francisco, and the stadium-sized, magnetic fusion ITER facility in France. But the U.S. Department of Energy is also hedging its bets through its ALPHA project, granting $30 million to leaner labs and startups to explore alternative methods.
The Swarthmore team is one of nine in that project, which is predicated on a hybrid approach of magneto inertial fusion (MIF). The teams will spend the next few years trying to succeed where traditional government funding has fallen short, in a competition The New York Times frames as “David and Goliath.”
“This program is giving voice and opportunity to other ideas that have been developing almost in the shadows over the last 20 years,” says David Schaffner, assistant professor of physics at Bryn Mawr College, who is collaborating with Brown for the ALPHA project. “You never know where the next big innovation is going to come from.”
ALPHA project leaders approached Brown at its outset, impressed with the small scale of SSX and hopeful that for the relatively small stake of $550,000, “they might get a lot of bang for their buck,” Brown says.
The SSX team is designing a magnetic blob that can be compressed — think smooshed — by one of the drivers being developed by other research teams. Brown describes it as “a twisted-up blob, kind of like a rope you twist up and connect back on itself.” The final product will look like a one-liter bottle, filled not with Coke but million-degree plasma.
“We’re viewing it as a kind of shot in the dark,” says Brown. “This has never been done before.”
The ultimate goal is to sell the Swarthmore blob to a company interested in compressing it. That market-based element of the project has been daunting for Brown, forcing a tight timeline.
“This isn’t an academic exercise where you can ponder and tinker," he says. “We’re all under the gun to meet the milestones and have something to show for that [$30 million] in three years.”
“It’s about understanding the physics behind everything that we’re doing and implementing it to achieve something bigger for the market,” adds Manjit Kaur, a postdoctoral research fellow who came to SSX from India this summer to help balance the mechanical and technical elements of the project.
Schaffner, who played a key role in Swarthmore’s successful application for the project while a postdoctoral research fellow here, is working with three students at Bryn Mawr to help establish the protocol at the SSX lab. The next phase is to build pulse modules to accelerate and evolve the plasma into elongated structures called Taylor states, which were discovered at Swarthmore by Brown and Tim Gray ’01 in 2013.
Then, the blob will be accelerated into the chamber, stalled, and compressed.
“I’m excited to see how much hotter, denser, and faster the plasma will become when we accelerate and confine it into a smaller chamber,” says Jeremy Han ’17. Han, a computer science and physics major from Cypress, Calif., is working on code for the project this summer while writing his thesis on the magnetic field structure of the Taylor states.
Another student, Jaron Shrock ’18, is building high-voltage equipment with tens of thousands of dollars worth of hardware loaned to SSX by Brown’s contacts from another MIF group, Tri Alpha Energy.
“I feel incredibly lucky to work on this project, contributing in a meaningful way to something that could help us explore new areas of physics,” says Shrock, an Honors physics and mathematics major from Buda, Tex. “That type of exploration is really the core of why I'm drawn to physics.”
Brown relates to that sentiment, having been intrigued by scientific discovery ever since he was a child.
“Fusion, in particular, just seemed like such a great idea,” he says. “You look to the sky and the stars and see that fusion energy is really what runs the universe. The sun and stars have been burning for billions of years, a beautifully efficient process that nature has given us.”
Turning his attention back to the present day, Brown reaches for a model of the twisted-up rope structure that’s sitting on his desk, and smiles.
“Even if we fail,” he says, “we’re exploring a region of plasma space, if you like, that hasn’t really ever been explored before.”