Type | Tokamak |
---|---|
Operation date | 1982–1997 |
Major radius | 2.1–3.1 m |
Minor Radius | 0.4–0.96 m |
Magnetic field | 6.0 T (toroidal) |
Heating | 51 MW |
Plasma current | 3.0 MA |
Location | Princeton, New Jersey, USA |
The Tokamak Fusion Test Reactor (TFTR) was an experimental tokamak built at Princeton Plasma Physics Laboratory (in Princeton, New Jersey) circa 1980. Following on from the PDX (Poloidal Diverter Experiment) and PLT (Princeton Large Torus) devices, it was hoped that TFTR would finally achieve fusion energy break-even. Unfortunately, the TFTR never achieved this goal. However it did produce major advances in confinement time and energy density, which ultimately contributed to the knowledge base necessary to build ITER. TFTR operated from 1982 to 1997.
TFTR was the world's first magnetic fusion device to perform extensive scientific experiments with plasmas composed of 50/50 deuterium/tritium (D-T), the fuel mix required for practical fusion power production, and also the first to produce more than 10 MW of fusion power.
In nuclear fusion, there are two types of reactors stable enough to conduct fusion: magnetic confinement reactors and inertial confinement reactors. The former method of fusion seeks to lengthen the time that ions spend close together in order to fuse them together, while the latter aims to fuse the ions so fast that they do not have time to move apart. Inertial confinement reactors, unlike magnetic confinement reactors, use laser fusion and ion-beam fusion in order to conduct fusion. However, with magnetic confinement reactors you avoid the problem of having to find a material that can withstand the high temperatures of nuclear fusion reactions.The heating current is induced by the changing magnetic fields in central induction coils and exceeds a million amperes. Magnetic fusion devices keep the hot plasma out of contact with the walls of its container by keeping it moving in circular or helical paths by means of the magnetic force on charged particles and by a centripetal force acting on the moving particles.
In 1986 it produced the first 'supershots' which produced many more fusion neutrons.
In experiments conducted during July 1986, the TFTR achieved a plasma temperature of 200 million kelvin (200 MK). This temperature was the highest ever reached in a laboratory. The temperature is 10 times greater than the center of the sun, but more important, it is more than enough for breakeven, which is the point where fusion produce as much energy needed to be expended to ignite them. Besides temperature, break-even requires another criterion: the product of plasma density and confinement time, usually called the triple product.