Mr. Robin Stafford Allen gave a fantastic talk on Nuclear Fusion and Energy. He told us why nuclear fusion could be very important in the future. The Earth's growing population as well as increasing wealth in developing counties means that the demand for energy is increasing. Mr. Allen showed us how renewable energy sources may not the answer as they are unreliable and relatively inefficient compared to burning fossil fuels, but also how fossil fuels are unsustainable for the future and contributing to global warming. So fusion might just be the answer. ITER - The World's Largest Fusion Experiment Mr. Allen went on to tell us the basics of what fusion is and how it can produce energy. In fusion, they use two heavy isotopes of hydrogen, Deuterium and Tritium to create Helium and a high energy neutron. In the process 0.4 of the mass of the nuclei is lost and released as energy. There is a lithium blanket that captures these energetic neutrons and fusion of the lithium and the proton occurs producing Helium, Tritium (which can be used in the main fusion reaction) and heat, this heat can be used to boil water, produce steam, drive a generator and produce energy. Reacting 1 gram of Deuterium and Tritium produces the same amount of energy as burning 10 million grams of coal or gas. Mr. Allen explained that if fusion is to occur the isotopes have to be heated and turn into a plasma, they are heated in three ways, Ohmic heating, Radio Frequency heating and Neutral beam heating. He said however if the plasma touches the walls of the reactor it would severely damage the machine, so to stop the plasma from doing this, a magnetic field is created to hold the charged particles away from the wall. Mr. Allen explained that to create this strong magnetic field they must use electromagnets, and for the field to be so strong a huge current has to run through the machine. But because of resistance, everything heats us very quickly so the machine can only be switched on for 15 seconds before it overheats and has to be turned back off and left to cool. This problem is in a reactor called JET in Oxford. Mr. Allen told us about a new reactor being built in France called ITER which uses superconductors so the machine can keep on running without heating up. However ITER has limited funding from governments and the high energy protons damage the materials that the machine is built from, but because high energy protons are only really produced in these fusion reactions there isn't a lot of research on resistant materials. Mr. Allen finished with telling us the many advantages to fusions, there are little or no environmental impacts, it doesn't produce only ‘long-lived’ radioactive waste and the resources needed are abundant in the Earths crust and water.
Written by Nina Mulder-Qureshi
0 Comments
Leave a Reply. |
AuthorOur blogs are written by the girls that attend this society. Archives
June 2020
Categories |