Scientists plan to ignite tiny man-made star Answered
"While it has seemed an impossible goal for nearly 100 years, scientists now believe that they are on brink of cracking one of the biggest problems in physics by harnessing the power of nuclear fusion, the reaction that burns at the heart of the sun.
In the spring, a team will begin attempts to ignite a tiny man-made star inside a laboratory and trigger a thermonuclear reaction.
Its goal is to generate temperatures of more than 100 million degrees Celsius and pressures billions of times higher than those found anywhere else on earth, from a speck of fuel little bigger than a pinhead. If successful, the experiment will mark the first step towards building a practical nuclear fusion power station and a source of almost limitless energy.
This is big medicine, because while we have (more or less) successfully harnessed the power in nuclear fission, we've yet to find a method of using nuclear fusion for power (outside of experimental/weaponry uses). It is important to note, however, that this initial experiment, while big, won't be powering your home or office just yet-even if it does work, there's still quite a lot that would have to be done to build a nuclear fusion power plant.
Still, it's heady stuff, the energy source of dreams-a world powered by nuclear fusion fueled by hydrogen, one of the most abundant elements in the universe-only now that dream is looking like it could, possibly, maybe, eventually, become reality.
And now, a word from our
sponser resident particle physicist:
The NIF at Livermore uses small (BB-sized) pellets of liquid hydrogen (technically a deuterium-tritium mixture) encased in a shell.
The pellet is illuminated by a terawatt laser split into 192 sub-beams all focused on a poiint. The outer shell of the pellet is vaporized and a shockwave compresses the hydrogen to the point where it should start fusion.
The whole process is over in roughly a microsecond. If you keep dropping pellets into the chamber, then you get a series of pulses, but as soon as you stop, everything shuts down.
The NIF (like the NOVA laser before it) is being run at a weapons lab, because the kind of fusion it can do (individual microsecond pulses) is most useful for studying the physics underlying thermonuclear weapons. It is probably not a viable technology for continuous power-generation fusion, but it is necessary for understanding how to make that sort of system work.