The gas used for maglev trains is helium.
A maglev train is a high-speed train that operates on the principle of using the interaction force between electromagnets and magnetic tracks to levitate the train so that it can travel at high speeds without touching the tracks. This levitation technology requires a special gas to make it happen: helium.
Helium is a rare gas that is colorless, odorless and non-toxic at room temperature and pressure, with a molecular weight of 4 and an atomic number of 2. Helium's density is very low, about half that of hydrogen, so it can be used as a filler gas in magnetic levitation trains.
In a maglev train, helium's main role is to provide levitation. Since helium has a very low density, the more it lifts the train upward, which lifts the train off the track. Also, because helium has a small molecular weight, it can pass through gaps between magnetic tracks more quickly, which allows the train to accelerate and decelerate more quickly.
Helium also has some other characteristics, such as not reacting with other substances, being non-flammable and non-explosive, that make it an ideal filler gas in maglev trains.
Applications of helium:
1, medical field: helium can be used in medicine to make helium-oxygen mixture, which is a kind of high-oxygen gas, commonly used in respiratory anesthesia and respiratory therapy. It can replace nitrogen in human respiration and increase the partial pressure of oxygen in human tissues, thus making surgery safer.
2. Industrial field: In industry, helium is widely used as a refrigerant and desiccant. It is a very ideal refrigerant because it is chemically stable and does not react with other substances. In addition, helium can be used for deep-sea diving and balloon flights because it is less dense than air and can rise into the atmosphere.
3. Scientific experiments: Helium also plays an important role in scientific experiments. For example, in superconductivity experiments, helium is an ideal coolant for cooling devices to very low temperatures so that they exhibit superconductivity.
4. Maglev trains: In the field of transportation, helium is used in maglev trains. Since helium has a very low density, it provides greater lift to levitate the train on the track, thus allowing the train to run at high speeds without touching the track.