Superconductivity applied to our life?
Superconductors developed by CERN to carry currents above 20,000 amps
Most chemical elements become superconducting at low enough temperature
Superconductivity allows electrical current to be conducted without loss of energy or resistance
Trains that circulate levitating, high precision magnetoencephalograms; and smaller and lighter motors, generators and transformers are some of the applications of superconductivity
A bit of history to situate ourselves
At the beginning of the 20th century, the Dutch physicist H. Kamerlingh Onnes and his team of researchers dedicated themselves to studying the properties of matter at very low temperatures, between -271 ° C and -259 ° C. In 1911 they observed that the electrical resistance of mercury tends to zero (disappears) below 4.2 K (-269 ° C). They had just discovered superconductivity. Their contributions in this field earned them the Nobel Prize in Physics in 1913.
Two More Nobel Prizes for Researchers Advancing Superconductivity
In 1957, J. Bardeen, L. Cooper and R. Schrieffer enunciated their theory, known as BSC, which for the first time explained almost all the properties of superconducting materials and which was recognized with the Nobel Prize in Physics in 1972. The theory BCS postulates that, in the superconducting state, there is an attractive interaction between electrons through the deformations of the metallic lattice that couple them into pairs (Cooper pairs). These pairs are capable of carrying current without the appearance of electrical resistance.
In 1986, J.C. Bednorz and K.A. Müller, at the IBM laboratories in Switzerland, discovered superconductivity in ceramic materials and at temperatures above the limit. This result was a revolution: they soon identified many materials capable of working at temperatures above the boiling point of liquid nitrogen (-196 ° C), which allows them to be cooled much more easily and economically. The discovery earned them the Nobel Prize in Physics in 1987. These families of materials, known as "high-temperature superconductors," SAT, have sparked technological interest in developing new applications for superconductivity.
The Joule effect and Cooper pairs
When the electric current circulates through a conductive wire, it heats up (as indicated, for example, by the color change in the heating elements of stoves or in the filaments of light bulbs). This phenomenon, called the "Joule Effect", is due to electrical resistance and occurs because electrons, when they move, collide with the atoms of the material. On the other hand, in a superconductor, the electrons form pairs (Cooper pairs) that move through the material (synchronizing with each other and with the oscillations of the atoms) carrying current without the appearance of electrical resistance.
When the resistance drops to zero, a current can flow inside the material without any energy dissipation because the material no longer resists the passage of electric current.
Cooper pairs move through the interior of the solid without friction.
What applications does superconductivity have in our lives?
Generate and conduct electrical currents with very low energy losses
Install superconducting cables in the electrical network that allow transporting the same power with lower energy cost, which benefits the environment.
Design much smaller and lighter motors, generators and transformers. For example, propulsion engines for ships and wind turbines.
The production of large magnetic fields
Improve the MRI equipment installed in hospitals: superconducting wires less than 1 mm in diameter allow the circulation of hundreds of amperes without losses, which makes them ideal for coils that generate very strong magnetic fields (higher to 2 teslas).
huge superconducting magnets (gray tubes)
New transport systems
Since superconductors can generate large magnetic fields, permanent magnet circuits can be built in which vehicles can (literally) levitate on them. This is the case of Maglev trains that, as friction with the track disappears, will reach speeds of up to 580 km / hour on the route between Tokyo and Osaka. The first commercial line is scheduled to enter service in 2025.
Design of new electronic devices
These high-performance electronic devices can detect very small magnetic fields and are used in high-precision scientific instruments. They are capable of detecting, for example, the magnetic fields induced by transmissions between groups of neurons in the brain and have already been used to obtain magnetoencephalograms.
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