Stellarators - The Future of Fusion Energy [2020]

this video is sponsored by the great courses plus tokamaks are by far the most studied type of fusion reactor in the world so much so that the European Union is investing billions of euros in one of the largest machines ever built by men the either project there are many other ideas being explored in terms of magnetic and inertial confinement while a lot of them are promising concepts energy production is still a big question mark stellar Raiders on the other hand offers a clever approach to fusion however due to the complexity of these machines usually they get more attention for its looks than its actual ingenuity hello everyone subject 0 here before we dive into today's topic a quick word from our sponsors my main goal for this channel is to demonstrate data in having information flow in a captivating and compelling way because of that one of the biggest challenges I face when crafting my channel's content is the lack of respectable reliable and up-to-date sources finding reliable 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the address shown here the great courses plus is subscription on-demand video learning service with top-notch lecturers courses are from Ivy League professors and other great universities globally and experts from places like National Geographic the Smithsonian and the Culinary Institute of America through your subscription you get access to a huge library of over 11,000 video lecturers about anything that interests you science math history literature and even how to cook play chess or become a better photographer to start your free trial just make sure to click on the link featured on the video description below or go to the address shown here now back to the video just like either the Vandal Stein 7x project has been in development for decades more precisely since the 1980s when the planning of the project started it was only submitted to the European Union in August 1990 followed up by a long bureaucratic period of application assessments concluded March 11 1996 it would take 19 more years for its first helium plasma test or the machines first test run on December 10th 2015 either on the other hand still has a long road ahead with its first test run set for 2025 with a current estimated cost of 22 billion euros but the expected final cost by 2040 is more than 80 billion the cost of the seven acts is currently 1.1 billion dollars or at least that was the best estimate that I could find online I gotta tell you though how difficult it was to find information about the seven acts so many days researching this topic and boy oh boy how difficult it was to find anything but anyway if we go by costs alone even if the seven acts real cost was ten times of that it would still be a better investment not only because it's cheaper but as we will see next it solves one of the most fundamental problems of magnetic confinement there are mainly two problems when it comes to fusion the heat transfer and the magnetic confinement in a nutshell fusion reactors are nothing more than glorified pressure pots using high-tech stuff the concept of energy production is very similar to fission like water reactors the main difference is that fusion releases more energy we have complete control over the reaction meaning if we stop feeding the machinery with fuel the reaction stops immediately and lastly it's not nearly as radioactive as fission in essence fusion can be achieved by heating atoms with 20 kilo electron volts and when they fuse they release more or less 20 million electron volts from that you get a neutron with 14 million electron volts that leaves the plasma and it's captured by the blanket which transfers the heat to a coolant which can either be liquid like water or gas like helium this is why the heat transfer is a problem in the case of the 7x it's one of the things that they are working on methodically to get it right in the next few years the blankets job is to make sure that the heat transfer happens precisely while protecting the outer parts of the machine remember we are talking about extreme temperatures separated only by a few centimeters graphite is a good candidate for the blanket but the problem with it is that if it decays due to the high temperatures it will contaminate the plasma hindering the fusion process the alpha particle that is emitted with 3.5 million electron volts remain in confinement to continue heating up the plasma now you are probably asking so if you need only 40 kilo electron volts and you get 3.5 million electron volts that is more than enough to get fusion going why don't we have fusion yet well the answer is quite simple not all atoms fuse which is a problem with the confinement then we must also understand they're more than 80% of the heat generated is used to make electricity while 20% keeps the plasma hot although you don't need much energy to initiate fusion you do need the atoms to collide and for that you need to increase the likelihood of collisions to happen that is when the magnetic confinement comes into play how a tokamak works is straight for you have a toroidal chamber which is a giant circular tube or torus with coils all around it like a solenoid this enables the plasma to be confined in the toroidal magnetic field so the plasma moves in a circular pattern the problem with this approach is that the confinement is killed towards the center of the torus due to the nature of the system and for a tokamak to be successful we need to even out the confinement to do that we introduce a second electromagnetic field using a transformer this generates a current inside the confinement chamber making the plasma twist which evens out the distribution and also heats it up the system has several disadvantages one of them being the length of the wires for the coils like I mentioned in my inner video they used 100,000 kilometres of niobium tin and/or niobium titanium for that if you want more information about this I suggest to watch my video about fusion another disadvantage is the drifting of atoms due to the magnetic confinement what this means is that the charged particles eventually are trapped by orbits that throws them out of the desired fusion orbit or they drift away from the magnetic lines to which it was supposed to follow in the first place basically the etherium and tritium are lost because of this significantly decrease in the chances of fusion to overcome this problem they have to make the magnetic confinement stronger which means bigger machine now you understand why error is so massive the vendor stein 7 acts offers a more elegant but complex solution to these problems how do we all think that stellarators are something new they are as oldest tokamaks Lyman Spitzer jr. was the man behind the idea what he tried to do was to find a way to eliminate the drifting of atoms in tokamaks like I explained earlier his key insight was to understand that by twisting the shape of the plasma it would somewhat eliminate drifting so he devised an experiment by turning the torus into an eight shaped tube in his first try he managed to heat the plasma to 500,000 Kelvin but not much more was concluded keep in mind that this was during the 1950's so achieving 500,000 Kelvin was quite a feat his second big insight was to realize that the H shape was not necessary what he really needed was to introduce helical field coils with currents at alternating directions throughout the length of the Taurus this alone would create the desired twisted magnetic field giving birth to the classical stellarator although this was a clever insight the problem of drifting atoms is still there it was only with the advancement of computers that de stellarators regain credibility supercomputers gave scientists the ability to understand how plasmas behave in extreme electromagnetic fields and by that they were able to design what is now the 7x shape in the magnetic field is crucial to any reactor and the 7x shines because of that it is comprised of a five fold symmetry torus that helps shape the plasma field lines this is important because it enables the machine to handle longer plasma times without the need of extra power this approach is more elegant in tokamaks for a few reasons it eliminates the necessity of a transformer to twist a magnetic field which dramatically decreases the amount of energy required by the machine while either we'll have a total magnetic field of 13 Tesla the 7x can work with only three to achieve the break-even State or so the hope wiring for coils are only a few hundreds of kilometers when compared to eaters on 100,000 kilometers this has also an impact on time to build a machine since getting this much wiring took almost eight years for it er stellarators can achieve stronger magnetic fields that do not require bigger machines to be obtained because of that confinement is many times better than tokamaks stellarators can operate as steady states much better because it has less magnetohydrodynamic activities at nearly disruption free states another advantage is the steady-state magnetic fields and the absence of current driven instabilities and disruptions something that is an intrinsic problem with tokamaks another reason why they have to go with bigger machines lastly is cost if it all goes well with the 7x which is only a proof of concept building a stellarator that can produce energy won't cost nearly as much as a project like either further optimizations such as going from a fivefold symmetry to a quasi symmetric fourfold symmetry which helps eliminate harmonics and produce a field line with single harmonic symmetry may help achieve that because it effectively eliminates toroidal curvature and dramatically improves particle confinement so far the seminars has been successful in every test and the last upgrade for its final phase is the installment of the actively cooled diverter using CFC this will enable the machine to handle plasmas for up to 30 minutes and it should be ready by 2020 the future of stellarators depends on this final test and if all goes well either will look really bad alright folks that's it we're done here [Music] you [Music]

Channel: Subject Zero Science

Views: 557,611

Rating: 4.879344 out of 5

Keywords: Subject Zero Science, graphene, clean energy, fusion power, lockheed martin, fusion energy, ted talk, graphene technology, graphene strength test, graphene battery, graphene production, fusion energy 2019, fusion energy news, fusion energy explained, fusion energy reactor, nuclear fusion, clean energy technology, renewable energy sources, renewable energy projects, renewable energy 101, nuclear fusion explained, nuclear fusion reactor, stellarator

Id: qKTePWmHRQw

Length: 12min 33sec (753 seconds)

Published: Sat Jan 11 2020

Reddit Comments

[u/VEC7OR]

Uh, see you in 20 years? or was it 30?

Also video begins at 3.00 mark.