Nuclear Fusion Breakthrough

One of the problems faced by those who are researching the potential of nuclear fusion as an energy source is that heretofore it has taken more energy to get atoms to fuse together than what's gotten out of the fusion.

The difficulty is this. The fuel for fusion is an isotope of hydrogen called deuterium. Deuterium contains one proton and one neutron in its nucleus. Because protons are positively charged and because like charges repel, it's exceedingly difficult to get two deuterium nuclei to be pressed close enough to each other for the strong nuclear force to take over and bind them together.

Only the pressures generated in the interiors of stars or in a nuclear explosion or by the focused beams of multiple high-powered lasers can force these deuterium nuclei to "smoosh" together.

And if they can be forced together a small amount of the matter in the nucleus is converted into energy according to Einstein's equation E = mc^2 where E is the energy produced, m is the mass that's converted and c is the speed of light. The speed of light is 3x10^5 km/s. That number squared is 9x10^10 so even a small amount of mass (m) multiplied by such a huge number results in an enormous amount of energy (E) being produced.

Which is why recent work done at Lawrence Livermore National Labs is so significant. Jim Geraghty fills us in at NRO:

Across the bay from San Francisco, the Lawrence Livermore National Labs have been conducting fusion experiments at the National Ignition Facility, a giant lab the size of a sports stadium, where the equipment “precisely guides, amplifies, reflects, and focuses 192 powerful laser beams into a target about the size of a pencil eraser in a few billionths of a second, delivering more than 2 million joules of ultraviolet energy and 500 trillion watts of peak power.”

If you smash two atoms together at exceptionally high speeds, they merge, and in the process release energy; for decades, researchers have been stymied by the challenge of generating a reaction that releases more energy than it consumes.

That, reportedly, is what the Department of Energy has done for the first time.

This is, however, just a first step. There are lots of hurdles to be surmounted. Geraghty quotes the Washington Post:

Creating the net energy gain required engagement of one of the largest lasers in the world, and the resources needed to recreate the reaction on the scale required to make fusion practical for energy production are immense.

More importantly, engineers have yet to develop machinery capable of affordably turning that reaction into electricity that can be practically deployed to the power grid.

Building devices that are large enough to create fusion power at scale, scientists say, would require materials that are extraordinarily difficult to produce. At the same time, the reaction creates neutrons that put a tremendous amount of stress on the equipment creating it, such that it can get destroyed in the process.

There’s a long way to go, and this is just the first step, but it is a key first step. The potential of this breakthrough is spectacular.

Fusion has numerous advantages over every other power source - fossil, green or nuclear - currently on the horizon. There's no radioactive waste or threat of a nuclear meltdown, no carbon footprint, and the fuel, deuterium, is found in water and is almost inexhaustable.

Geraghty has more about this development at the link, but however exciting this breakthrough is we're still a long way from being able to use fusion to produce commercially marketable electricity. Even so, the Lawrence Livermore people have taken a giant first step.