Fusion in the Early Years

(Inside Science) -- Dennis Whyte of Massachusetts Institute of Technology explains the early history of fusion energy.

“The history is interesting of this. It was actually pursued quite vigorously in the heart of the Cold War in the 1950s. People at that point had studied the basic nuclear process, about how those two come together to fuse. We had measured that. We knew the rate that that happened. And considering about how fast fission had gone from basically being a laboratory demonstration to being used on submarines and producing small-scale reactors, people thought that that would repeat itself.

“And really there was a race on actually, because we thought, ‘Oh, this is going to be like five years away,’ or something like that. So, what was underestimated was the difficulty of basically understanding that complete state of matter, the plasma, because everything’s so hot when you make fusion happen, it has to be in the plasma state. That actually wasn’t understood about how difficult that was going to be. And what really amounted was that an entire new discipline actually had to be grown from scratch almost, about how you control, stabilize, and contain and understand, actually, a plasma. Again, this is a very complex object. It’s at over -- it’s over 10 million degrees of temperature, and it’s just a very complex state. So, it took a long time for that to be understood.

“It was declassified actually because people realized it isn’t right at hand. And then around 1970 the Russians, or the Soviet Union at that time, actually invented a new -- had a new configuration called a tokamak, which is a Russian acronym, that actually got past that barrier of 10 million degrees for the first time.

“The timing was also interesting that it occurred in the ’70s, so that there was a promise of this looked real because you had high enough temperatures that you could start thinking, ‘Oh, this is actually going to work,’ and the results of the energy crisis of the 1970s. So, what happened was this enormous boom that happened, a large amount of investment, new experiments in a very fast period of time, sort of on the order of 20 years.

“We went from that state of just seeing it kind of works, to a point where these devices were producing over 10 million watts of fusion power.

“But in order to get net energy, this thing, this plasma, has to make more fusion power of course than the power used to keep it hot; otherwise it’s not a net energy system.”