A joke that nuclear engineers like to tell is that commercial nuclear fusion power is a technology that is 50 years away and has been for decades. ZME Science reports a new engineering breakthrough that might shorten that time considerably.
The way that a standard fusion reactor, called a tokamak, works is that hydrogen isotope atoms are smashed together to form helium and a great deal of energy. The resulting plasma, which is hotter than the cores of stars, is contained by powerful magnets that also serve to sustain the fusion reaction.
The problem is that previous controlled fusion experiments have consumed more energy to sustain the reaction than the reaction produced. This problem is where the new breakthrough, developed by researchers at MIT, comes in.
The MIT engineers have developed new magnets made of rare-earth barium copper oxide (REBCO) superconducting tapes. Magnets made of the new material create a magnetic field almost double the strength of magnets that have hitherto been used.
The development means that the plasma can be confined to a smaller space, which means that the fusion reactors can be built smaller and more cheaply. More importantly, doubling the strength of the magnetic field increases the energy produced by the fusion reaction 10 to 16 times previous results, more than enough to make the reactor a practical generator of limitless, clean energy.
The design of the reactor using the new magnets will be much like the $40 billion tokamaks being built in France, but for a fraction of the cost and a fraction of the time it takes to build. The reactor will be able to sustain a fusion process, unlike the French tokamak, which can only create a fusion reaction for few seconds. Thus, the innovation may cause a fusion future to at last become a reality.