“Prior breakthroughs have been important but it’s not the same thing as generating energy that could one day be used on a larger scale.” “This is very important because from an energy perspective, it can’t be an energy source if you’re not getting out more energy than you’re putting in,” Friedmann told CNN. Otherwise, it doesn’t make much sense for it to be developed. While there’s many more steps until this can be commercially viable, it’s essential for scientists to show that they can create more energy than they started with. Why was today's announcement significant? This is the first time scientists have ever successfully produced this, instead of breaking even as past experiments have done. “Hydrogen is found in water so the stuff that generates this energy is wildly unlimited and it is clean.” “Unlike coal, you only need a small amount of hydrogen, and it is the most abundant thing found in the universe,” Julio Friedmann, chief scientist at Carbon Direct and a former chief energy technologist at Lawrence Livermore, told CNN. Tritium is rarer and more challenging to obtain, although it can be synthetically made. The deuterium from a glass of water, with a little tritium added, could power a house for a year. Fusion projects mainly use the elements deuterium and tritium – both of which are isotopes of hydrogen. Scientists around the world have been studying nuclear fusion for decades, hoping to recreate it with a new source that provides limitless, carbon-free energy – without the nuclear waste created by current nuclear reactors. Nuclear fusion happens when two or more atoms are fused into one larger one, a process that generates a massive amount of energy as heat. What is nuclear fusion and why does it matter? Nuclear fusion is a man-made process that replicates the same energy that powers the sun. Here are key things to know about today's announcement - and possible next steps: Scientists at Lawrence Livermore National Laboratory’s National Ignition Facility have made history by successfully producing a nuclear fusion reaction resulting in a net energy gain, a breakthrough hailed by US officials as a “landmark achievement” and a “milestone for the future of clean energy.” (Jason Laurea/Lawrence Livermore National Laboratory) Three types of moderators are used at the MIT reactor: (1) ordinary or "light" water that is also used to cool the reactor core, (2) deuterated or heavy water (D 20), and (3) high-purity graphite, both of which are excellent at slowing neutrons without absorbing them.NIF Target Area operators inspect a final optics assembly during routine maintenance at Lawrence Livermore National Laboratory’s National Ignition Facility. Since U-235 nuclei do not readily absorb the high energy neutrons that are emitted during fission, it is necessary to slow the neutrons down with a "moderator". In the MIT reactor, one other group of components is essential to the maintaining and controlling a chain reaction. As fewer and fewer neutrons are absorbed, more and more neutrons are available to cause the splitting of uranium nuclei, until finally enough neutrons are available to sustain a chain reaction. To put the reactor into operation, the control blades are raised very slowly. When the control blades are fully inserted, they absorb so many neutrons from the uranium that there are not enough to allow a chain reaction to continue. Boron has the property of absorbing neutrons without re-emitting any. The rate of fissions in the uranium nuclei in the MIT reactor is controlled chiefly by six control blades of boron-stainless steel which are inserted vertically alongside the fuel elements. When it is in operation, the central active core contains a huge number of neutrons traveling in every direction at very high speeds. The MIT Research Reactor is used primarily for the production of neutrons. Hence, the possibility exists for creating a chain reaction. Each time a U-235 nucleus splits, it releases two or three neutrons. This process is known as fission (see diagram below). When a U-235 nucleus absorbs an extra neutron, it quickly breaks into two parts. The arrangement of particles within uranium-235 is somewhat unstable and the nucleus can disintegrate if it is excited by an outside source. In the nucleus of each atom of uranium-235 (U-235) are 92 protons and 143 neutrons, for a total of 235.
0 Comments
Leave a Reply. |