KAI ZHANG zhangkai@mail.utexas.edu Nuclear Fusion Power KAI ZHANG zhangkai@mail.utexas.edu Oct.27 2005
Sun How dose sun work? Where dose the energy come from?
Instruction What is the nuclear fusion power? Advantages. Research bottle neck. Experimental reactor. Future.
What is nuclear fusion power? Fusion power is the power that drives the stars. it is based on fusing light nuclei such as hydrogen isotopes to release energy. In the core of the sun at temperatures of 10-15 million degrees Celsius, Hydrogen is converted to Helium providing enough energy to sustain life on earth.
Nuclei of two isotopes of hydrogen, deuterium (D) and tritium (T) react to produce a helium (He) nucleus and a neutron (n). A lot of energy is liberated at the same time:
Advantages of Fusion power Abundant Fuel Supply--water No Risk of a Nuclear Accident since any malfunction results in a rapid shutdown. No Air Pollution leading to "greenhouse" effect. No High-level Nuclear Waste No Generation of Weapons Material
Conditions for a Fusion Reaction High Temperature Over 100 million deg. C Isolation Hot plasma must be well isolated away from other material surfaces High fuel density The density of fuel ions must be sufficiently large. Refill fuel fast and remove Helium fast.
Solutions so far High temperature: Isolation-Magnetic field 1. Large current heating-7 million amperes (7MA) 2. High speed neutral beam heating-140,000 volts 3. Radio-Frequency Heating-20MW 4. Current Driven by Microwaves heating Isolation-Magnetic field plasma consists of two types of charged particles, so magnetic fields can be used to isolate it from the vessel walls
Experimental reactor-Europe JET plant
Experimental reactor-Europe JET plant
> Big Problem: the power required to maintain the reaction the power generated by the fusion reaction > High temperature High magnetic field High fuel density
Big event: ITER Project Future: It is still very far away from really using the nuclear fusion power. A lot of research work need to be done. People are still not sure if it is economical enough comparing with other forms of power Big event: ITER Project The European Union, the United States, Russia, Japan, South Korea and China are going to build the largest nuclear fusion plant in France and try to achieve the targets of a self-sustaining reaction and a net energy gain. http://www.iter.org/
Thanks !