Introduction to Fusion Energy Research Prospects, promises and problems: An introduction to the physics and policies behind fusion energy Anne E. White Assistant Professor, Department of Nuclear Science and Engineering, MIT January 14, 2014 MIT PSFC IAP Seminar Series whatisfusion.org Overview of this talk • Introduction to fusion • Inertial confinement fusion • Magnetic confinement fusion • Survey of research programs around the world • The Future January 14, 2014 MIT PSFC IAP Seminar Series 2 FUSION Nuclear Fusion is a physical process, combing light nuclei (e.g. hydrogen) to make heavier nuclei (e.g. helium). Process that powers the stars. Fusion Energy Research refers to an entire branch of science dedicated to harnessing fusion processes; to build a fusion reactor, and build a fusion power plant There has been tremendous progress in fusion energy research in recent years Fusion energy research pushes frontiers of science and technology Fusion energy research is an exciting, fast-moving international research area January 14, 2014 MIT PSFC IAP Seminar Series 3 Matter and Energy The equivalence is described by the famous equation* where E is energy, m is mass, and c is the speed of light. *Nature 438, 1096-1097 (22 December 2005) | doi:10.1038/4381096a; Published online 21 December 2005 January 14, 2014 MIT PSFC IAP Seminar Series 4 Four Fundamental Forces of Nature Strong force: Weak Force: Holds atomic Needed to build up heavy nucleus together nuclei in periodic table; Transforms quarks 1 Stronger 10-6 Weaker 1/137 -39 60 Electromagnetism Gravity Interactions between charged Attraction of objects particles, exchange of photons with mass to each other January 14, 2014 MIT PSFC IAP Seminar Series 5 • Electromagnetic force: when you rub balloon on your hair, when you play with magnets, when you use a battery… • Electromagnetic force: holds atoms together in molecules, holds molecules together (chemistry) • Gravitational force: objects dropped fall to earth Moon orbits earth http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html Earth orbits sun January 14, 2014 MIT PSFC IAP Seminar Series 6 Nuclear forces: • The nucleus contains protons (+) and neutrons (no charge) Oxygen Atom • Protons (+) in nucleus want to repel each other due to electromagnetic forces Oxygen • Nucleus is held together Nucleus by the strong force (nuclear force) • Powerful enough at atomic scale to overcome repulsion January 14, 2014 MIT PSFC IAP Seminar Seriesof protons (+) 7 Four Fundamental Forces of Nature Strong force: Weak Force: Holds atomic Needed to build up heavy nucleus together nuclei in periodic table; Transforms quarksForces of nature 1 are harnessed to Stronger -6 10transform energy from Weaker one form to 1/137another -39 60 Electromagnetism Gravity Interactions between charged Attraction of objects particles, exchange of photons with mass to each other January 14, 2014 MIT PSFC IAP Seminar Series 8 Units to measure energy and power “Joule” or “J” is a unit of Energy “Watt” or “W” is a unit of power 1 Joule Power is energy used per second 1 Watt = 1 second Your 60 Watt light bulb uses 60 Joules of energy per second A 60 W incandescent light bulb, tungsten A “60 W equivalent” CFL filament Actually is only 13 W : Same time, less power, less $ January 14, 2014 MIT PSFC IAP Seminar Series 9 How much energy is a “Joule” anyway ? Lifting World Series Trophy Hard thrown football (60 mph) above your head (30 lbs) 60 Joules 150 Joules Hard hit baseball (100 mph) 1000 Joules January 14, 2014 MIT PSFC IAP Seminar Series 10 Chemical Energy 15 20 40 kJ/g kJ/g kJ/g mii.org Nuclear Energy FISSION FUSION 50 350 Million Million kJ/g kJ/g January 14, 2014 11 Matter and Energy •Electromagnetic force: Burning materials breaks chemical bonds releasing stored energy • Coal power plant •Your car’s gas engine • Your fireplace •Gravitational force: Falling water transforms potential energy into kinetic energy • Hydroelectric power plant •Nuclear Force: Uranium interacts with low energy neutrons, breaking apart via fission reactions • Fission power plant January 14, 2014 MIT PSFC IAP Seminar Series 12 Most of the Energy in the US is produced from gas and coal causes problems of pollution, climate change effects January 14, 2014 MIT PSFC IAP Seminar Series 13 Humans use a lot of energy Global Energy Production per Year ~ 4 x 1020 J The US contributes 25% of this total ~ 1020 J/year per person in the US ~ 10 kW per person in the US per year Fusion energy can contribute to solving world’s energy problems January 14, 2014 MIT PSFC IAP Seminar Series 14 Fission refers to breaking apart heavier nuclei to make lighter nuclei Nuclear binding energy is released in the process • A low energy neutron 50 Million (room temperature) kJ/g •Because neutron is neutral, it can interact at close range with a big positive (+) charged nucleus •Excited nucleus will split apart, releasing nuclear energy in the process, and more neutrons •Produced neutrons can cause another fission reaction •Chain reaction January 14, 2014 MIT PSFC IAP Seminar Series 15 Fission is so easy, the Earth has done it naturally! http://www.ans.org/pi/np/oklo/ • Oklo (former Republic of Gabon) Uranium ore samples showed lower 235U concentrations than found elsewhere; lower than normal • Depletion of 235U through fission only way 2 Billion year-old fossil this could have happened • Oklo had 235U underground, in water, … 2 Billion years ago, there was a natural nuclear (fission) reactor • Other evidence: Neodymium (Nd) & Ruthenium(Ru) http://www.wired.com/wir isotopes from ore match reactor concentrations not edscience/2010/06/early- natural abundancesJanuary 14, 2014 MIT PSFC IAP Seminar Seriesmulticellularity/ 16 Fusion to make fusion power plants … Hughes IAP 2013 January 14, 2014 MIT PSFC IAP Seminar Series 17 Fusion to make fusion power plants … Hughes IAP 2013 January 14, 2014 MIT PSFC IAP Seminar Series 18 Why Fusion? Pros • Abundant, high energy density fuel (D + Li) • No greenhouse gases (nor NOX, SOX, particulate emission) • Safe – no chain reaction, ~1 sec worth of fuel in device at any one time • Minimal “afterheat”, no nuclear meltdown possible • Residual radioactivity small; products immobile and short-lived • Minimal proliferation risks • Minimal land and water use • No seasonal, diurnal or regional variation – no energy storage issue Cons • We don’t know how to do it yet (turns out to be a really hard problem) • Capital costs will be high, unit size large (but with low operating costs) 19 1/15/2014 MIT PSFC IAP Seminar Series Why is Fusion so hard? 20 1/15/2014 Fusion is the opposite process of fission • Fusion requires light nuclei, isotopes of hydrogen D and T to get very close to each other • To overcome the electromagnetic force of repulsion (+) vs. (+) the nuclei must have a lot of energy Temperature of D and T fuel must be > 100 Million degrees Fusion is hot! Fusion cannot happen naturally on Earth January 14, 2014 MIT PSFC IAP Seminar Series 21 You may have heard of cold fusion… “cold” compared to millions of degrees needed for hot fusion (e.g. the sun) Cold fusion gained attention after reports in 1989 by Stanley Pons and Martin Fleischmann, With electrochemical device fusion… And again in 2002 when Rusi Taleyarkhan and collaborators claimed to have observed evidence of sonofusion… Claimed that their apparatus produced heat (energy) of a magnitude only http://www.economist.com/science/displayStory.cfm?story_id explained by a 490 nuclear processJanuary –SCIENCE 14, 2014 MIT PSFCFICTION IAP Seminar Series 22 You may have heard about a teen building a fusion reactor in the basement…or the garage… “Conrad Farnsworth, Wyoming Teen, Builds Nuclear Fusion Reactor In Garage” Conrad built a fusion reactor. SCIENCE FICTION Conrad built a device that generated fusion reactions. SCIENCE FACT http://iec.neep.wisc.edu/ Fusion reactions are produced in table top (small) devices all the time. You too can build an – look here: http://www.fusor.net/. Or here http://iec.neep.wisc.edu/ http://www.huffingtonpost.com/2013/02/04/conrad- farnsworth-builds-nuclear-fusion-reactor- garage_n_2616998.html The neutrons generatedJanuary 14, 2014 are MITused PSFC IAPin Seminara variety Series of 23 applications … but NOT FUSION ENERGY Table top fusion does happen…and it is very useful ! Shoot beams of atomic nuclei at other atoms Fusion of deuterium atoms (D + D) results in the formation of a He-3 ion and a high energy neutron Neutron generators have applications in medicine, security, and materials analysis. •Used to determine quality of oil Can’t make these fusion devices •Used in homeland security, airport luggage into fusion reactors* screens For fusion energy applications, Compact•medical Neutron applications, Generators for Medical, medical Homeland research Security, and Planetary Exploration, Reijonen, J, roceedings of 2005 Particle Accelerator Conference, Fusion must be hot. 100 Mill degrees! Knoxville,•Laboratory Tennessee : neutron49–53 source for other experiments Naranjo, B., Gimzewski, J. & Putterman, S. Nature 434, 1115−1117 (2005); *known physics doi:10.1038/nature03575 January 14, 2014 MIT PSFC IAP Seminar Series 24 When you heat anything to 100 Million degrees you create a new state of matter - PLASMA 25 1/15/2014 AEWhite NUF 2013 PLASMAS behave in very complicated ways, Need new branch of physics to deal with this • Very hot (minimum 5 eV; 60,000°K) – Electrons stripped from atomic nuclei – Excellent electrical conductivity – Significant interaction with electromagnetic fields and radiation • Quasi-neutral – But small deviations lead to strong plasma-generated electric and magnetic fields • The quest for controlled fusion energy led to the rapid development of the science of plasma physics – Important for understanding of astrophysics, space sciences, etc. 26 Hold hot (1 Million degree) plasma together for fusion • Gravitational Confinement (300 W/m3) – In a deep gravitational well, even fast particles are trapped.