In light of our troubled environment, one of the world’s most important pursuits involves the search for a source that can provide clean and unlimited energy. Basically, it’s a quest to find another sun, or at least a way to replicate our sun’s energy production process through a machine that can produce and control searing balls of plasma gas.
Right now, we have nuclear fission — the process of splitting atoms to generate energy. It’s successful in generating energy, but it fails in the ‘clean’ aspect as it produces much radioactive waste.
And then there is nuclear fusion. Instead of splitting atoms, the process involves bonding together of atoms, specifically, hydrogen atoms being subjected to high temperature and pressure until they combine to form helium atoms and release hot, charged plasma gas. Aside from using only seawater as fuel, this process can theoretically generate limitless energy, minus any harmful and toxic by-products.
Currently, there are two types of machines that have the potential to successfully bring about nuclear fusion — the tokamak and the stellarator.
A tokamak is a donut-shaped device that makes use of 2D magnetic fields (created by electric current passing through rings of magnets) to trap plasma long enough to allow nuclear fusion to take place.
On the other hand, a stellarator works by generating 3D magnetic fields, in twisted configurations instead of symmetrical rings, which makes it possible to contain the plasma without the need for any electrical current.
Compared with the tokamak which is dependent on electrical current and is therefore prone to disruption and incomplete fusion, the stellarator seems more stable because it only relies on the twisted magnetic fields it generates to hold the plasma in until fusion takes place. The challenge lies in making sure the magnetic fields are strong enough.
A few days ago, a team of US and German scientists working since last year on a stellarator — the Wendelstein 7-X (W 7-X) stellarator — has confirmed that their device is working as it should, producing magnetic fields that were as close as possible to their intended design.
According to their report published in Nature Communications, they were able to measure the error rate and it was impressively low at less than one in 100,000.
While the W 7-X stellarator isn’t designed to be the energy generator itself, proving that it is capable of producing the required magnetic fields is enough reason to move forward — use its concept and design to build the kind of reactor that we are envisioning, our own man-made sun.
And so the race to build the first fully functioning nuclear fusion machine has just become more interesting. On one end is ITER, France’s tokamak reactor. On the other end is the W 7-X stellarator, the result of collaborative work between Germany’s Max Planck Institute of Plasma Physics and the US Department of Energy. Both devices have shown the capability of containing plasma long enough to allow fusion to occur. We hope that soon enough, one or both will succeed in making nuclear fusion a reality.