The magnet being worked on inside the test stand. A low-temperature superconductor would need a volume 40 times bigger to achieve the same field strength. This material is applied as a ribbon-like tape, and it allows them to create a much stronger magnetic field in a much smaller space. The MIT team, and their commercial partner, a startup named Commonwealth Fusion Systems (CFS), surpassed their competitors by applying a new superconducting material to the magnets: a high-temperature superconductor. Previous attempts at a net-positive reactor have used conventional copper electromagnets, and more recently, low-temperature superconductors, to contains the fusion reaction. By working to improve the magnets, the MIT team hopes to be the first to finally produce a reactor that makes more energy than it uses. The problem is that, so far, they always take more energy to run than they produce (keeping those magnetic fields up to contain the plasma uses a lot of energy). Artificial fusion reactions have been produced before.
The real ground-breaking work here isn’t the fusion itself. MIT scientists hope to arrange their powerful new magnets into a tokamak reactor, and in doing so produce net-positive nuclear fusion (fusion that produces more energy than it uses) by 2025. The most common shape for one of these magnetic bottles is a donut-like object known as a tokamak. A strong magnetic field can do just that, creating an artificial ‘bottle’ in which nuclear fusion can occur. The solution, proposed as early as the 1950s, is to contain the plasma without letting it touch anything. Nuclear fusion only occurs at immensely high temperatures – the plasma must reach temperatures that would melt or destroy any material that humans could think to build a reactor out of. This is where MIT’s powerful new magnet comes in. Credit: Gretchen Ertl, CFS/MIT-PSFC, 2021 Designed and built by Commonwealth Fusion Systems and MIT’s Plasma Science and Fusion Center (PSFC). If a commercially viable fusion reactor could be made a reality, it could quickly become the energy source of the future. When artificially reproduced on Earth, it is far less prone to catastrophic explosions than fission is, and it produces far less radioactive waste. This is the kind of reaction that occurs in the Sun and stars. Nuclear fusion, on the other hand, relies on combining two atoms together to make a larger one. It’s effective, but can be dangerous, and leaves behind long-lasting nuclear waste which is difficult and expensive to store safely. Current nuclear power plants use fission – the splitting of atoms – to produce electricity. Nuclear fusion has been the holy grail of clean energy for decades now, but it’s a difficult nut to crack. Reaching 20 Teslas (a measure of field intensity), this magnet could prove to be the key to unlocking nuclear fusion, and providing clean, carbon-free energy to the world. On September 5, 2021, a team of MIT researchers successfully tested a high-temperature superconducting magnet, breaking the world record for the most powerful magnetic field strength ever produced.
0 kommentar(er)
