14 DAY TRIAL // Plasma is a very hot, ionized gas that conducts electricity and has a main role in the fabric of stars.
The principle is simple: if we heat hydrogen ions to the point of ignition, they could fuse into helium and this fusion could be a clean, sustainable and endless energy source.
And if the Sun does it, converting 400 tons of hydrogen into helium each second, couldn't we do it as well?
Well...not yet, but we're trying hard.
Current plasma research is based on two types of magnetic plasma confinement devices; tokamaks and stellarators.
Tokamaks, currently in the first place in the fusion race, work by driving a current through the plasma itself, resulting in plasma currents, which provide part of the magnetic field that confines the plasma.
But these are subject to frequent disruptions and instabilities in the plasma field.
On the other hand, a few lengths back is the stellarator, that doesn't have currents, and so, no disruptions, but they have the tendency of losing high rates of energy, during transport.
Partially, the external magnetic coils are to blame here for the high transport rates in conventional stellarators.
Add some ripple to the magnetic field and the plasma can get trapped in the ripple and lost.
But now, the underdog makes an unexpected comeback: a research team from the University of Wisconsin, headed by electrical and computer engineering Professor David Anderson and research assistant John Canik, recently proved that the Helically Symmetric eXperiment (HSX), a new type of plasma chamber, can overcome the major barrier in plasma research, in which stellarators lose too much energy to reach the high temperatures needed for fusion.
The HSX is the first stellarator to use a quasi-symmetric magnetic field.
The reactor itself looks postmodernistic: twisted magnetic coils wrap around the warped doughnut-shaped chamber, with instruments and sensors coming in and out of the device.
But the semi-helical coils that give the HSX its unique shape also direct the strength of the magnetic field, confining the plasma in a way that helps it retain energy.
Well, they claim to have solved most of the problem, because "the slower energy comes out, the less power you have to put in, and the more economical the reactor is," says Canik.
This discovery is an important breakthrough in the way coils are being engineered, and they hope to some day integrate their technology into a new class of fusion generators that could bring the dream of constructing a piece of the Sun on Earth closer to reality.