Maglev is a special type of high-speed train, which can reach speeds of over 500 km per hour. It got its name from the combination of the words magnetic levitation, on which principle it works. The first fog patent was developed in the 1970s in America, and German and British specimens soon followed. Today, they are still a rarity and are in commercial use in only a few countries, most of which are in Japan.
- What types of fast trains exist?
One type of fog works on the principle of electromagnetic field. Its rails are made of iron, and the electromagnets that are attached to the outside of the bottom of the train enable levitation.
Magnetic levitation is a technology based on magnetism in which one object hovers (levitates) over another without any mechanical support, only with the help of a magnetic field.
Another principle of fog operation is based on the use of superconductors and magnetic rails.
- What is a superconductor?
Superconductivity occurs with certain materials at low temperatures, where there is a complete absence of electrical resistance and quenching of the internal magnetic field. Then a miraculous quantum phenomenon occurs, so that the electric current can flow through that field practically without resistance.
When it is cooled to about -196 degrees Celsius with liquid nitrogen, the superconductor does not allow magnetic lines of force to penetrate and rely on them. This is professionally called the Meissner effect.
Superconductivity research has become very popular in the last few decades, and maglev is one of the first practically used technologies.
The Center used superconductors made of yttrium-barium-copper-oxide (YBa2Cu3O7) to construct its fog.
- How does the train move?
Liquid nitrogen is poured on the place in the vehicle where the superconductors are, and in order for the vehicle to start, it is necessary to push it a little with your hand. The material is cooled with liquid nitrogen and then becomes superconducting. He then lifts the train, because an unusual and very strong magnetic field is formed around it, which makes every metal that is nearby float. When the liquid nitrogen evaporates and the superconductor temperature is equal to the room temperature, the vehicle stops.
- Can ordinary magnets produce this effect?
Ordinary magnets are not strong enough to support a train. Neodymium magnets (Nd) are needed, the strongest magnets of today, which are used in electric motors, computers, wind generators, etc. The magnet magnets of the Center for the Promotion of Science have a strength of 1.28 T.
- What are the advantages of such trains?
If we boarded a train like this in Belgrade, we would be in Novi Sad in 15 minutes. Its high speed is a consequence of the absence of friction between the train and the rails. In Japan, there are experimental lanes that have reached speeds of up to an incredible 900 km per hour. Also, these types of trains do not use fossil fuels, which pollute the environment.
- How does the fog exhibit made by the Center for the Promotion of Science work?
Maglev, who will be presented by the Center in cooperation with the Faculty of Physics at the Festival, belongs to the other group. Therefore, instead of an electromagnet, it has a superconductor, and the rails are made of special earth magnets. Any type of fog can work on this principle.