The US Fusion Ignition Breakthrough EXPLAINED

last week in the USA the Lawrence Livermore National ignition facility achieved net energy gain in a fusion experiment for the first time ever more energy out than they put in a major scientific breakthrough decades in the making it proves definitively that the long sought after goal the Holy Grail of fusion can indeed be achieved however there are quite a few asterisks after that statement today I want to do a few things I want to take a look at what happened I also want to look at the groundwork however that is still needed to bring Fusion fully to life to see whether finally we have crossed this precipice as it being maybe less than a decade away but first let's do a quick refresher on what is Fusion [Music] foreign ters at the moment use fission the splitting apart of heavy elements to create energy the elements that we most commonly use are uranium and plutonium for fission reactions and nuclear power plants because they are some of the easiest to get the process started and reasonably easy to control once the process has begun the energy released by fission in these reactors heats water into steam to drive turbines to ultimately generate electricity never forget that all of human history can essentially be summarized as finding new ways to boil water the big downside of fission though is that it has the unfortunate consequence of producing radioactive material as a byproduct which we typically have to capture and then usually store deep underground forever Fusion by comparison is the same process used by the Stars it occurs when light atoms like hydrogen and helium are pushed so close together that they spontaneously fuse hence fusion into One releasing energy G as heat and I always get the question okay I understand why breaking apart releases energy but why does fusing two things together release energy surely it takes energy to do that process in a fusion reaction two light nuclei merge to form a single heavier nucleus the process releases energy because the total mass of the resulting single nucleus after Fusion is less than the mass of the two original nuclei so in this instance one plus one doesn't equal 2 it equals a little bit less than two the leftover Mass becomes energy directly from Einstein's E equals MC squared now why is that Fusion process so difficult for us to achieve on Earth to push those two light atoms together they have to collide at incredibly high speeds remember particle speed is just temperature so you need to raise these particles up to incredibly high temperatures more than about a hundred million Centigrade which is about 10 times hotter than the center of the sun this sounds strange because why do we need to create something hotter than the sun if the sun itself is capable of fusion well it's because the sun is cheating because the gas in the sun is under such high pressure meaning the atoms are packed much much much closer together than we could ever get them here on Earth about 10 times denser than lead it doesn't need to be as hot to start that Fusion process in the sun it turns out that the sun is actually pretty inefficient at doing Fusion it's just so huge there's just so many atoms in it that there's a lot of opportunity for Fusion events to happen facilitating the process on earth needs to be significantly more efficient you might have heard of a popular type of fusion called confinement Fusion which is the typical kind of donut structure that you might see around Fusion experiments these use superconducting magnets to squeeze ions close enough together to cause them to fuse but the national ignition facility is working on a very different approach called inertial Fusion which I always like to refer to as causing something to implode faster than it has time to explode what could possibly go wrong [Music] the nif is about the size of three football fields primarily split up into two pieces the laser system and the target facility where the fusion event actually takes place the laser system starts by generating a pulse in the master oscillator a pulse of laser lights which is broken then into 192 separate laser beam paths that propagate in total about 1 500 meters before they reach the target they go through a series of amplification spatial filtering and polarization steps to give them a clean and even power distribution across each beam line as well as to make sure that each beam arrives at the target at exactly the same time the laser system is something called a pulsed laser unlike something like a laser pointer say that uses a continuous beam the nif fires a short and intense pulse of laser light so the tricky part here is to get each beam incident on the target arriving at the Target at exactly the same time if they do though as those beams hit the target they deliver about two megajoules of UV energy into the Target in a few billionths of a second the Target or whole room whole room whole room whole ROM the Target or whole room is a hollow cylinder about the size of a Tic Tac inside a Target is the capsule around the size of a small BB which is composed of deuterium and tritium two pretty rare elements to find on Earth but which are the Fusion fuel that the system will try to ignite the laser beams aren't actually directed specifically at the capsule but rather the internal walls of the target doing so heats the walls to tremendously high temperatures to the point where they start to produce x-rays these x-rays evenly distribute the energy onto the capsule contained within this begins to superheat and abellate essentially burn off the outside of the capsule it creates an equal and opposite force on the core of the capsule heating it and compressing it causing the light atoms inside to collide together and hopefully kick-starting the fusion reaction now you might be asking yourself that sounds easy why is this process so hard well even slight inaccuracies in the timing of those lasers or imperfections in how round that capsule is could mean that the capsule isn't evenly heated that's one of the major areas that the teams at the nif have had to tackle in order to actually achieve the fusion yields that they were looking for on December 5th this process finally put out 3.15 megajoules for the 2.05 megajoules input by the laser we had fusion and we had a net energy gain now the level of complexity to achieve this is obviously worth celebrating in its own right but did we do it are we on our way to unlimited clean energy now one of my problems around journalism in Fusion experiments is that the idea of net energy gain in this sort of experiment is a little bit fuzzy around the edges just how efficient this Fusion experiment actually is is always a bit of a kind of blurred line I don't think this is necessarily duplicitous I don't think people are out there to try and trick anyone not research labs and not startup companies trying to create Fusion what is actually happening I think is just different priorities among these different systems what groups like The Naf are actually trying to understand is how does Fusion work and what are the important parameters in how it behaves achieving net gain is important to them but understanding the science is really their focus this is Fusion on kind of a proof of concept level is it actually viable now it's worth introducing at this point one of the most powerful tools in the Arsenal of the physicist the circle or in 3D the sphere which helps us to Simply defy almost any problem if we put a circle around the target like the nif are doing the energy in 2.0 megajoules is definitely less than the energy that comes out 3.15 megajoules this measurement of net gain is something called the scientific Q value and by this metric we absolutely have our successful Fusion experiment however to you and I as the awaiting recipients of utopian energy production our interest is always on the and when does it actually become useful to us kind of end of the spectrum if we expand our Circle to include the entire laser system say this tells a slightly different story the laser draws about 300 megajoules to deliver the fusion yield of 3.15 megajoules if we're only getting three megajoules out of the fusion reaction actually suddenly now we're looking more like one percent efficiency rather than 150 efficiency now this might initially be disheartening link but I don't think it should be the amount of energy in this sort of experiment isn't really the point the experiment is designed to test Fusion not deliver economic efficiency the national ignition facility is about 20 years old and a lot of the components date back to the 1990s and Laser Technology has progressed significantly since that point the nifs laser wall plug efficiency is about 0.5 percent but modern day lasers can be between 20 to 30 percent efficiency which could make a significant impact in making Fusion viable swapping out the system used to generate the laser is absolutely necessary for commercial Fusion but absolutely unnecessary to measure and understand how Fusion processes actually behave there is still significant further engineering work to be done here but it's definitely not as bad as that initial one percent efficiency number the main fuel source for Fusion at nif is a mixture of hydrogen Isotopes deuterium and tritium true in particular is incredibly rare on Earth there are maybe a few kilograms total available across the entire planet so thinking about our global system we also need to consider the energy costs of developing further fuel sources bringing all these constraints together the Q value for viable Fusion is most commonly cited as around 15 to 30 x so about a 10 times Improvement on the December result one of the biggest engineering challenges to cover off though is to produce a version of inertial confinement that can be repeatedly fired and the energy captured efficiently maybe hundreds thousands or millions of times or cycles per day at the moment the nif is designed to load and fire about once a day one of the most compelling Visions for how to solve this problem that I've seen is First Light Fusion I made a video on that earlier this year which you can check up somewhere out here first light are an inertial confinement startup based in Oxford that fires a projectile at their fuel to initiate Fusion rather than hitting it with lasers their early plans Envision a repeatable firing system using essentially a railgun to launch their projectiles with the heat captured and recycled through a continuous flow of liquid lithium interestingly first light Fusion have also just announced their plans to open a 570 million pound tritium Factory to ensure cheaper and reliable fuel for nuclear fusion reactors still obviously a major work in process but just solidifying that commercial entities looking at Fusion are actually trying already to solve these sorts of problems but still it begs the question are we there yet no [Music] the question we may need to ask ourselves is is that generation capability going to come online in time to have any meaningful dent in solving problems like climate change and moving us away from fossil fuels the likelihood in all honesty in my opinion is probably not but does that mean we shouldn't progress that line of research well no I think even if those Solutions come on 20 30 years down the line having access to them and the understanding that comes with it will absolutely be a paradigm shift in how energy is generated unlocking understandings not only about fundamental physics and how fusion and plasmas behave but also bringing to Bear more engineering technologies that otherwise wouldn't have been developed as a necessity of solving the pieces of the problem that prevent Fusion from being a reality today to turn fusion into a power source we'll need to boost the energy to find ways to rapidly reliably and cheaply reproduce Fusion events before it becomes a viable means of power production it's really hard to say how quickly we will get there but with the results that we saw from the nif we now know that fusion power is absolutely Within Reach foreign [Music] [Music]

Channel: Dr Ben Miles

Views: 746,560

Keywords: science, startup, spinout, research, how to run a business, business, innovation, future, investment, deep tech, deep science, future technology

Id: j2WOp4hIcYk

Length: 13min 35sec (815 seconds)

Published: Wed Dec 21 2022