When I was a kid, I had a subscription to Popular Science. I’m sure this isn’t precisely right, but it seemed that almost every issue featured hovercrafts, tilt-rotor aircraft, or nuclear fusion. When I was a teen, I subscribed to the now-defunct, and at first very cool, Omni. Nowadays, I subscribe to Scientific American (and understand about two-thirds of it).
Generating power through nuclear fusion offers the prospect of unlimited energy (all you need is sea-water), emissions-free. The government has spent billions and billions of dollars on fusion research.
Every article I read had fusion ‘just around the corner’ – about 20 years down the road. Well, here we are 20 years later, and the Department of Energy funding has spent 13 years building the National Ignition Facility, which to date has cost approximately $4.2 billion. It’s designed to produce for the first time, a net gain of energy – previous efforts have always ‘cost’ more energy than is produced.
Great news, right? Well, it looks like we’re still at 20 years away, at least. The current Scientific American has a piece (subscription required), that says that moving from ‘ignition’ to commercial feasibility is going to be a very hard, and probably a very long row to hoe.
Apparently, firing 192 lasers to strike within 6 picoseconds, a 2mm pellet of deuterium/tritium chilled to –275 Centigrade, heating it to 100 million degrees (10x hotter than the center of the sun, it becomes the highest temperature in the solar system), is the easy part.
Issues range from sustaining the reaction, to the neutron emissions that cause serious damage to the confinement chamber, to getting the heat out, to a bunch of other things that people way smarter than me, haven’t figured out how to do yet (like firing the lasers 4x a second, rather than the once every other day they can do now).
This isn’t to say it won’t ever happen, and we should keep plugging– if it works, it will change the planet, and probably the course of civilization; and I hope I’m wrong, but it’s probably something that’s going to be enjoyed by our children, or their own children. Sort of like a full-length Second Avenue Subway.
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