CAMBRIDGE, Mass. A unique MIT laboratory is back in business. The Plasma Science and Fusion Center was shut down for more than a year due to federal budget cuts. But scientists are once again at work, creating and controlling the energy of the stars, and possibly the power source for our planet’s future.
The Power Source Of The Future?
Even though Dr. Earl Marmar’s lab is just across the street from his office at MIT, the senior scientist puts on his coat. The day is bright and sunny but deceptively cold. It’s 20-something degrees outside, a stark contrast to inside his lab, where things really heat up.
“We’ve gotten to 100 million in our experiment — that’s centigrade or Kelvin,” Marmar explains. That’s about 200 million degrees Fahrenheit, about 10 times the temperature in the center of the sun. Marmar’s experiments are ambitious and audacious.
But it’s all in a days work at MIT’s Plasma Science and Fusion Center, where for the past 20 years scientists have conducted experiments using a reactor known as “Alcator C-Mod” to create and control the energy source of the stars.
Scientists, graduate students and engineers huddle over computer screens and stare at giant monitors in the front of the control room. It looks like you’d imagine: space-age, high-tech, with the lived-in look of a college dorm.
The Alcator C-Mod reactor, made from special tungsten alloy-steel, weighs 100 tons. It’s the size of a one-car garage and shaped like a giant bagel.
Inside, powerful magnets — 160,000 times as powerful as the Earth’s magnetic field — do what atom-crushing pressures in the core of stars do: They force hydrogen nuclei to fuse and, in the process, release unearthly amounts of energy.
“This is a unique facility in many ways,” explains the lab’s associate director, Martin Greenwald. “This is the highest magnetic machine in the world.”
Greenwald stands by as the Alcator C-Mod reactor powers up, filling with hydrogen that’s been turned into a plasma — a weird fourth state of matter that’s not a gas, a solid or a liquid. Then a powerful electric current — 1 to 2 mega amps — is zapped into the giant, bagel-shaped, steel device.
How big is a mega amp? The equivalent of 1 to 2 million 100-watt light bulbs.
“It’s sort of industrial science,” Greenwald says.
For a few brief seconds, MIT physicists create the power of the stars and capture it in a magnetic bottle. “When we run the machine, we make fusion,” Greenwald says.
The ultimate goal: to build a steady state reactor that keeps going like the sun and could power a city.
The fusion lab has the most employees and the biggest budget of any experiment on campus. It’s as big as science gets at MIT, in large measure because the promise is so great — a fusion reactor produces energy with virtually no deadly radioactive waste. It can’t possibly explode and the fuel is deuterium, derived from hydrogen, the most abundant element in the universe.
“If you took a glass of water, you extract the deuterium out of that, which would be a very small amount, and then you put it into a fusion reactor, you would get as much energy as about 300 glasses of gasoline,” Greenwald says. “And there’s a lot of water in the world.”
It almost sounds too good to be true.
“If you list all the advantages compared to fossil fuels, renewables and fission, it’s all good,” Greenwald says. “It sort of wins everywhere. And then there’s one con, which is that it’s really hard technically. And that’s the challenge we have to meet.”
But as difficult as fusion’s many technical challenges are, Marmar says the most immediate difficulty has been financial: federal funding to keep the Alcator C-Mod reactor running.
Fourteen months ago, Congress cut funding for MIT’s fusion center in half from $28 million to $14 million. While there was still enough to pay salaries for a year and work on past research results, there was no money to run the reactor.
Layoff notices were sent out, prompting a quarter of the scientists, engineers and technicians to leave. And the center’s 30 grad students faced career-altering choices.
“We stopped taking new students for two years, and we concentrated on helping students who were here, who were a little bit left in the lurch in some cases, to actually finish up,” Marmar says.
One of those left out in the lurch was grad student Bob Mumgaard.
“That’s one of the reasons I got involved in this,” he says. “You can look around and there’s a lot of really interesting sciences out there, but in terms of an area where you can look and say, as a young person, I can be a part of something that could be a really big deal and can make an impact. So looking at the field of fusion you can see that.”
While the fusion reactor was shut down, Mumgaard worked on side projects. He began writing his thesis and considered his next move, possibly China. The U.S. has about 200 to 300 fusion grad research students. China has 2,000 to 3,000 and an ambitious fusion program.
“I’d probably have gone overseas where the funding is maybe more secure and long term,” Mumgaard says. “It would have been a problem. I possibly would have left the field.”
But late last month Congress restored most of MIT’s fusion budget and renewed the U.S. financial support for an international fusion reactor being constructed in France. It’s based on MIT’s reactor but will be 10 times bigger and more powerful, designed to prove commercial fusion power is possible.
“We think you could put electricity on the grid in 20 to 30 years, but that would require a real crash program,” Greenwald says. “At the rate we’re now going, it would be longer. Fifty years is more like the kind of number.”
Critics of fusion research joke that it’s the energy source of the future, and always will be. But with Alcator C-Mod reactor once again creating the conditions of the center of stars in a lab at MIT, Marmar has renewed hope.
“The whole system of funding of science in the United States is one year at a time. That’s the way it works,” he says. “I think [the future of fusion at MIT is] very bright. It’s very promising. We’re very optimistic at this point.”