Do you remember in 1989 when two chemists announced they’d created a setup that created nuclear fusion at room temperature? Everyone was excited, but it eventually turned out to be very suspect. It wasn’t clear how they detected that fusion occurred and only a few of the many people who tried to replicate the experiment claimed success and they later retracted their reports. Since then, mentioning cold fusion is right up there with perpetual motion. Work does continue though, and NASA recently published several papers on lattice confinement fusion which is definitely not called cold fusion, although it sounds like it to us.
The idea of trapping atoms inside a metallic crystal lattice isn’t new, dating back to the 1920s. It sounds as though the NASA method uses erbium packed with deuterium. Photons cause some of the deuterium to fuse. Unlike earlier attempts, this method produces detectable neutron emissions characteristic of fusion.
The fusor consists of a cross-shaped chamber, which is pumped down to a high vacuum to enable the fusion reaction to occur. Deuterium is then pumped into the chamber, and confined by an applied electric field from a power supply in the vicinity of 50 kV. With the right combination of geometry, vacuum and other factors, it’s possible to fuse atoms and observe the characteristic glow of the reaction taking place.
In order to be recognised as having achieved fusion by the Open Source Fusor Research Consortium, one must typically have proof of the release of neutrons from the fusion reaction. [Jackson] showed this with a neutron detector setup, by inserting and removing it during a run to demonstrate the fusor was the source of the signal. Photos of the glowing fusor don’t go astray, either, and [Jackson] was more than happy to deliver.
Many of us have held a circuit board up to a strong light to get a sense for how many layers of circuitry it might contain. [alongruss] did this as well, but, unlike us, he saw art.
We’ve covered some art PCBs before. These, for the most part, were about embellishing the traces in some way. They also resulted in working circuits. [alongruss]’s work focuses more on the way light passes through the FR4: the way the silkscreen adds an interesting dimension to the painting, and how the tin coating reflects light.
To prove out and play with his algorithm he started with GIMP. He ran the Mona Lisa through a set of filters until he had layers of black and white images that could be applied to the layers of the circuit board. He ordered a set of boards from Seeed Studio and waited.
They came back a success! So he codified his method into Processing code. If you want to play with it, take a look at his GitHub.
An experimental fusion reactor built by the Chinese Academy of Science has hit a major milestone. The Experimental Advanced Superconducting Tokamak (EAST) has maintained a plasma pulse for a record 102 seconds at a temperature of 50 million degrees – three times hotter than the core of the sun.
The EAST is a tokamak, or a torus that uses superconducting magnets to compress plasma into a thin ribbon where atoms will fuse and energy will be created. For the last fifty years, most research has been dedicated to the study of tokamaks in producing fusion power, but recently several projects have challenged this idea. The Wendelstein 7-X stellarator at the Max Planck Institute for Plasma Physics recently saw first plasma and if results go as expected, the stellarator will be the design used in fusion power plants. Tokamaks have shortcomings; they can only be ‘pulsed’, not used continuously, and we haven’t been building tokamaks large enough to produce a net gain in power, anyway.
Other tokamaks currently in development include ITER in France. Theoretically, ITER is large enough to attain a net gain in power at 12.4 meters in diameter. EAST is much smaller, with a diameter of just 3.7 meters. It is impossible for EAST to ever produce a net gain in power, but innovations in the design that include superconducting toroidal and poloidal magnets will surely provide insight into unsolved questions in fusion reactor design.
If you’re looking for the future of humanity, look no further than the first plasma generated in the Wendelstein 7-X Stellerator at the Max Planck Institute for Plasma Physics. It turned on for the first time yesterday, and while this isn’t the first fusion power plant, nor will it ever be, it is a preview of what may become the invention that will save humanity.
For a very long time, it was believed the only way to turn isotopes of hydrogen into helium for the efficient recovery of power was the Tokamak. This device, basically a hollow torus lined with coils of wire, compresses plasma into a thin circular string. With the right pressures and temperatures, this plasma will transmute the elements and produce power.
Tokamaks have not seen much success, though, and this is a consequence of two key problems with the Tokamak design. First, we’ve been building them too small, although the ITER reactor currently being built in southern France may be an exception. ITER should be able to produce more energy than is used to initiate fusion after it comes online in the 2020s. Tokamaks also have another problem: they cannot operate continuously without a lot of extraneous equipment. While the Wendelstein 7-X Stellerator is too small to produce a net excess of power, it will demonstrate continuous operation of a fusion device. [Elliot Williams] wrote a great explanation of this Stellerator last month which is well worth a look.
While this Stellerator is just a testbed and will never be used to generate power, it is by no means the only other possible means of creating a sun on Earth. The Polywell – a device that fuses hydrogen inside a containment vessel made of electromagnets arranged like the faces of a cube – is getting funding from the US Navy. Additionally, Lockheed Martin’s Skunk Works claims they can put a 100 Megawatt fusion reactor on the back of a truck within a few years.
The creation of a fusion power plant will be the most important invention of all time, and will earn the researchers behind it the Nobel prize in physics and peace. While the Wendelstein 7-X Stellarator is not the first fusion power plant, it might be a step in the right direction.
The magnum opus of alchemy was the Philosopher’s stone, a substance that was able to turn common metals into gold. Unlike alchemists, [Carl Willis] might not be poisoning himself in a multitude of ways, but he did build a Farnsworth fusor that’s capable of turning Hydrogen into Helium.
To fuse Hydrogen in his device, [Carl] first evacuates a vacuum chamber. Deuterium (Hydrogen with an added neutron) is injected into the chamber, and a spherical cathode made of Tungsten is charged to 75 kV. The deuterium gas is heated and confined by the cathode and fuses into Helium. The electrostatic confinement of the plasma isn’t very much different from some old CRT tubes. This isn’t a coincidence – both the fusor and CRTs were invented by the same man.
While no fusion experiments – including some billion dollar experiments – have ever produced a net energy gain, this doesn’t mean it’s not an impressive engineering feat. If you’d like to try your hand at building your own fusor, drop by the surprisingly active research forum. There’s a lot of really good projects to look through over there.