GRETCHEN ERTL
The concept is simple: Fill the doughnut with hydrogen gasoline, after which warmth that gasoline till it turns to electrically charged plasma. On this ionic state, plasma could be held in place by magnets positioned across the tokamak. Reaching fusion on Earth with out the immense stress of a star’s inside, scientists calculated, would require temperatures almost 10 occasions hotter than our solar’s heart—round 100 million levels Celsius. So the trick could be to droop the new plasma so completely in a surrounding magnetic discipline that it wouldn’t contact internal surfaces of the chamber. Such contact would immediately cool it, stopping the fusion response.
The nice half about that was security. In a failure, a fusion energy plant wouldn’t soften down—simply the other. The dangerous half was that gaseous plasma wasn’t very cooperative—any slight irregularity within the chamber partitions may trigger destabilizing turbulence. However the idea was so tantalizing that by the mid-Nineteen Eighties, 75 universities and governmental institutes world wide had tokamaks. If anybody may get fusion—probably the most energy-dense response within the universe—to work, the deuterium in a liter of seawater may meet one particular person’s electrical energy wants for a yr. It will be, successfully, a limitless useful resource.
In addition to turbulence, there have been two different huge obstacles. The magnets surrounding the plasma wanted to be actually highly effective—which means actually huge. In 1986, 35 nations representing half the world’s inhabitants—together with the US, China, India, Japan, what’s now the complete European Union, South Korea, and Russia—agreed to collectively construct the Worldwide Thermonuclear Experimental Reactor, a $40 billion big tokamak in southern France. Standing 100 toes tall on a 180-acre website, ITER (the acronym additionally shaped the Latin phrase for “journey”) is supplied with 18 magnets weighing 360 tons apiece, produced from the perfect superconductors then accessible. If it really works, ITER will produce 500 megawatts of electrical energy—however not earlier than 2035, if then. It’s nonetheless beneath building. The second impediment is the most important: Many tokamaks have briefly achieved fusion, however doing so all the time took extra power than they produced.
After incomes his doctorate in 1992, Whyte labored on an ITER prototype at San Diego’s Nationwide Fusion Facility, taught on the College of Wisconsin, and in 2006 was employed by MIT. By then, he understood how large the stakes have been, and the way life-changing commercial-scale fusion power may very well be—if it may very well be sustained, and if it may very well be produced affordably.
MIT had been making an attempt since 1969. The purple brick buildings of its Plasma Science and Fusion Heart, the place Whyte got here to work, had initially housed the Nationwide Biscuit Firm. PSFC’s sixth tokamak, Alcator C-Mod, inbuilt 1991, was in Nabisco’s previous Oreo cookie manufacturing facility. C-Mod’s magnets have been coiled with copper to function a conductor (consider how copper wire wrapped round a nail and related to a battery turns it into an electromagnet). Earlier than C-Mod was lastly decommissioned, its magnetic fields, 160,000 occasions stronger than Earth’s, set the world document for the best plasma stress in a tokamak.
As Ohm’s regulation describes, nevertheless, metals like copper have inner resistance, so it may run for less than 4 seconds earlier than overheating—and wanted extra power to ignite its fusion reactions than what got here out of it. Just like the now 160 comparable tokamaks world wide, C-Mod was an fascinating science experiment however primarily strengthened the joke that fusion power was 20 years away and all the time could be.
Annually, Whyte had challenged PhD college students in his fusion design courses to conjure one thing simply as compact as C-Mod, one-800th the size of ITER, that would obtain and maintain fusion—with an power achieve. However in 2013, as he neared 50, he more and more had doubts. He’d devoted his profession to the fusion dream, however until one thing radically modified, he feared it wouldn’t occur in his lifetime.
The US Division of Vitality determined to cut back on fusion. It knowledgeable MIT that funding for Alcator C-Mod would finish in 2016. So Whyte determined he would both give up fusion and do one thing else or attempt one thing totally different to get there quicker.
