Researchers from Princeton University have figured out how to stabilize the super hot, dense plasma in a nuclear fusion reactor by replicating the suns own “magnetic flux pump.”
Plasma – the fourth state of matter is a hot conglomerate of ionized gas and subatomic particles. Most plasma exists beyond the environment we experience every day here at ground level.
Originating from deep within the sun, where temperatures are so hot atoms break apart and fuse together releasing immense bursts of energy – ordinary gas atoms lose or gain an electron during this process, creating an “ion” that leaks electomagnetic waves (i.e. light). These gas ions then float around in a soup of their own dislodged electrons and this “soup” is called plasma.
Plasma eventually make it’s way over to Earth on a highway of “interplanetary flux ropes” where they enter the atmosphere and move around magnetic clouds – contributing to global weather patterns
Scientists figure they can harness the power of electrified plasma for clean energy by replicating the extreme conditions found on our sun. The hope being that they can reach those same temperatures high enough to break apart and merge atoms together in a “nuclear fusion reactor”
However in order to do this with our modern day technology they would need to spinthe gas in an isolation chamber whilst simultaneously heating it up to temperatures approaching the surface of our sun. They’ve hypothesized that this can be accomplished with a bunch of superconducting foil surrounded by a durable torus shaped chamber.
The largest project, called “Tokamak” is an international collaboration between nation’s around the world set to finish construction around 2025.
However the problem is that plasma oscillates unpredictably in both density in temperature making it difficult to stabilize. That is called “saw-tooth instability” so scientists ran several simulations of how to stabilize plasma. Nowadays computing power is great enough to test complex physical systems without having to actually build them out.
They discovered through the simulation of something called “magnetic flux pumping” whereby plasma is stimulated by a regular contracting and expanding magnetic field akin to the one surrounding our sun and others stars, that they could control the oscillation of plasma and reduce Saw tooth instability.
The key to deforming the magnetic field in just the right way to stabilize plasma is through keeping the current flat in the core of the reactor and making sure that the plasma remains sufficiently pressurized enough to create what is called a “quasi interchange mode” that mixes plasma together in order to avoid whatever inhomogeneities could lead to sawtooth instability.
This research was led by Isabel Krebs, post-doctoral research associate, who talked about the future applications of this discovery saying, “This mechanism may be of considerable interest for future large-scale fusion experiments such as ITER.”