What’s the application? The goal of laser ignition fusion experiments is to heat and compress a target to the point where the nuclei of the atoms making up the sample fuse together to form a new, heavier nucleus, releasing energy in the process. Nuclear fusion is, of course, what powers stars, and creating fusion in the laboratory has been the holy grail (well, a holy grail, at any rate) of nuclear physics research for the last sixty-plus years.
What problem(s) is it the solution to? 1) “Can we create fusion reactions in a laboratory setting on Earth?” 2) “How can we get more helium without mining it from the Moon?”
How does it work? The basic idea is appealingly simple: Get a whopping hug laser, focus it down onto a target, and BLAM! instant star:
In practice, it’s much more difficult than the idea makes it sound– you can very easily blast a target into plasma, but getting that plasma hot and dense enough to let fusion occur requires incredible care in arranging the beams so that the target is uniformly illuminated, and collapses in a symmetric manner.
But stripped down to its essence, that’s really all there is to gigantic experiments like the National Ignition Facility (WARNING: auto-playing video with sound): You just build the biggest laser you can, focus it down to a point, and blast away.
Why are lasers essential? You could theoretically do this with any really bright light source, but the current record is about 0.7MJ of energy in the pulse hitting the target, which would be awfully tough to arrange without a laser. Having the light pulse in laser form makes it vastly easier to direct and focus it appropriately.
Why is it cool? Dude, they’re, like, bringing the sun down to Earth!
Controllable fusion reactions in a lab setting would be a huge boon to nuclear research. And, of course, if scientists can figure out a way to generate power from nuclear fusion, they could
be gunned down by assassins hired by the Eeeeevil oil companies provide clean energy for the entire world.
Why isn’t it cool enough? They’ve made a lot of progress recently, but have not actually achieved fusion yet, though they hope to reach the required pulse energies this year, maybe. Commercial fusion power generation is twenty years off, and expected to remin that way for the next twenty-odd years.