1Good morning, everyone, and today we begin a short series on nuclear fusion as an energy source.
2Fusion is the process that powers the sun, where light atomic nuclei join together and release enormous energy.
3Unlike nuclear fission, which splits heavy atoms, fusion produces no long-lived radioactive waste of that kind.
4For decades, scientists have joked that practical fusion is always thirty years away from us.
5That joke hides a genuine difficulty, because the fuel must be heated to millions of degrees.
6At such temperatures, no solid container can hold the plasma, so powerful magnets are used instead.
7The early experiments of the seventies consumed far more electricity than they ever managed to produce.
8Contrary to popular belief, the recent breakthroughs in America did not deliver a working power station overnight.
9What the famous experiment actually achieved was a small net gain of energy in controlled laboratory conditions.
10The project was originally expected to report in spring, but the announcement finally came in December.
11What I want to emphasize is that scientific feasibility and commercial viability are two very different things.
12In the next lecture, we will examine the international reactor being constructed in the south of France.