Welcome to Brainstuff from house stuff Works dot com where smart happens him Marcill Brain with today's question, how does fusion power work? And will we ever have fusion power plants anytime in the near future? If you think about it, the Earth is already powered by one fusion power plant. The Sun is a gigantic fusion reactor that creates nearly all the energy making life on Earth possible. Sunlight provides the warmth that keeps water from freezing, and sunlight let's
plants create the food that makes animal life possible. What if we could take the fusion principles seen in the Sun and bring them down to Earth in a miniaturized form. If we could do that, it would be possible to generate all the electricity that humanity uses. We would not need to release any more of the carbon and pollutants generated by coal fired power plants, and we could also do away with most of the high level nuclear waste
produced by traditional nuclear power plants. Scientists and engineers have been working on fusion power for decades. Why are there no fusion power plants on Earth today? It's because it is very difficult to create a mini sun on planet Earth. The temperatures involved are mind boggling. Let's look at the basic idea behind fusion to understand where the temperatures come from. Hydrogen atoms are very common on Earth. Each water molecule,
for example, contains two of them. The goal of a fusion reaction is to press two hydrogen atoms together so tightly that their atomic nuclei fuse with each other to create a single helium atom. The nucleus of any hydrogen atom contains one proton. The nucleus of any helium atom contains two protons, so if you fuse the two hydrogens together, you get a helium The problem is that protons have no desire to get together because they have the same charge.
They repel each other in a way that's similar to magnetic propulsion. When you try to press the north poles of two magnets together, you can feel that repulsion, which gets stronger as the two magnets get closer together. That same kind of repulsion happens when trying to press the protons of two hydrogen atoms together. One way to get hydrogen atoms diffuse into helium atoms is to use a
nuclear bomb to generate the appropriate temperatures and pressures. Hydrogen bomb, also known as a fusion bomb, is a two stage weapon. The first stage is a traditional uranium powered fission bomb that explodes towards a capsule containing tritium and deuterium, which are two forms of hydrogen. The tritium and the deuterium fused together to create helium. As the helium has created a huge amount of energy is released, As we see in the sun. That energy takes the for orm of
heat and light. This second stage fusion reaction that takes place inside a fusion bomb is what makes a fusion bomb so powerful. Hydrogen bombs prove that fusion is possible on Earth and extremely powerful. However, they also show how messy the process can be. The goal of fusion research is to tap into the power in a controlled way that eliminates the explosion. One technology that's been used to contain the temperatures needed for fusion is called a tokeomac.
A tokomac looks like a donut shaped cavity surrounded by magnets. The magnets allow a ring of energetic hydrogen plasma to be created at the center of the hollow donut, so the plasma doesn't touch the walls of the chamber. If the plasma is heated to a hundred plus million degrees celsius, hydrogen atoms start fusing to create helium atoms. At that point, the heat of fusion keeps the plasma hot and the reaction becomes self sust daining. The extra heat produced can
be converted into electricity. A second way to create a fusion reaction is to burn a little bit of fuel at a time. In this approach, powerful beams of laser light focus on a tiny capsule of hydrogen think peppercorn in size. For this capsule, the lasers provide the heat to initiate a fusion reaction, which then extinguishes itself because the amount of fuel is so small. At this point in the research process, scientists are about to build a tokemac that may be large enough to contain a real
self sustaining reaction. It's called I T E R. And scientists have built and are currently testing a laser facility that may demonstrate the principles needed to build an eventual power plant. It's called the National Ignition Facility. But these are huge facilities and are extremely expensive to build, So the research process is slow and deliberate. It may be several more decades before a large, reliable fusion power plant
designed emergence from all this research. For more on this and thousands of other topics, esit how stuff works dot com and don't forget to check out the brain stuff blog on the house stuff works dot com home page. You can also follow brain stuff on Facebook or Twitter at brain stuff hs W. The how Stuff Works iPhone app has arrived. Download it today on iTunes