The world’s largest nuclear fusion machines have been just fired for the first time announced the physicists in Germany. The machine was successfully able to contain ‘plasma’, which are nothing but super-hot blobs of helium gas. A type of nuclear fusion device called a stellarator, the 16-metre-wide machine is the Wendelstein 7-X (W7-X). Stellarators are extremely difficult to construct. It took scientists about 19 years of to construct W7-X. This is the first time a team has demonstrated that it can produce and control plasma just as well as other fusion reactor designs. The Max Planck Institute for Plasma Physics tweeted out this unbelievable image of its new machine’s first plasma on December 10: Nuclear fusion occurs when atoms fuse together at incredibly high temperatures and generate energy in the process. This is the same process that has been fueling our Sun for about 4.5 billion years and will continue to do so for another estimated 4 billion years. The reason that the scientists are so excited about the process is that it has the ability to generate an almost-unlimited supply of energy from little more than salt water. In contrast to nuclear fission, which powers today’s nuclear power plants, nuclear fusion also doesn’t generate any radioactive waste, and is a whole lot safer. For the scientists it was incredibly tricky to achieve, as it requires them to construct a device that can generate and control a 100 million degrees Celsius (180 million degrees Fahrenheit) blob of plasma. The key to controlling plasma is to use super-chilled magnetic coils to generate powerful magnetic fields that contain and control the plasma. Scientists have already built several working doughnut-shaped fusion reactors known as tokamaks. However, there is a huge problem with totamaks, as it can only control the plasma in short bursts that last for no more than 7 minutes. Further, the energy necessary to generate that plasma is more than the energy engineers get from these periodic bursts. In other words, Tokamaks consume more energy than they generate. That’s why the launch of the stellarator makes it so exciting, as it is predicted that it could sustain a plasma for at least 30 minutes at a time, which is significantly longer than any tokamak. In its first run, the machine was filled with helium – an unreactive gas – heated with a laser to around 1 million degrees Celsius. This plasma was maintained for around one-tenth of a second, which may not sound like much, but was enough to show the machine works. “We’re very satisfied. Everything went according to plan”, said Hans-Stephan Bosch, who led the team. The next step is to increase the duration of helium plasma discharges, with the ultimate goal of building them up to 30 minutes in length. In January, the scientists will start trying to produce plasma from hydrogen, which is what would be used in a functioning nuclear fusion machine. It has never been the point of W7-X to generate energy. In order to show that the stellarator concept actually works, this device is simply used as a proof-of-concept. If everything goes according to the plan, it will help us build the next-generation of stellarators from the things we learn from W7-X, which could quite literally change the world, and end our dependence on fossil fuels forever. Or as aptly put by this commenter on YouTube: “Help us Wendlestein 7-X, you’re our only hope.” Resource: ScienceAlert
