Liquid helium: unique properties and applications areas
Helium, like other substances, can be in three states: solid, gaseous and liquid. Its natural essence, more usual role – inert gas. However really unique chemical and physical properties are characteristic of helium in the form of liquid. What it is, what qualities it has and where it is used – further.
What is liquid helium and what properties is remarkable?
Liquid helium is the corresponding aggregate state of one of the main elements of the inert group of gases. In the periodic system of chemical elements of Mendeleev, the substance is located under the second number, indicated by the Latin letters “He.” It has no color, smell or taste.
Helium is one of the most common elements in the universe, globally its volumes are second, just after hydrogen. However, on Earth, the distribution is quite rare, the bulk of the resulting material – in natural gas, with a concentration of up to 7% by weight. Obtaining a substance in liquid form for a long time was accompanied by difficulties, numerous attempts by scientists were unsuccessful. Only in 1908 managed to get helium-liquid, thanks to throttling technology. We will not go into technical details – this topic requires high detail and a lot of time. Now we will focus on the outstanding properties of the material, which explain the considerable demand for it in our time.
Helium is one of the lightest and has one of the lowest boiling points, which allows you to maintain low and ultra-low temperature parameters. At normal pressure, the liquid temperature is less than -269 ° C, and the density is 0.13 g/cm3. In appearance it is a colorless transparent material with an extremely low ability to refract light, so it is quite difficult to see it. It’s also super-fluid and the coldest element. Superfluidity and superheat conductivity of liquid helium are those characteristics that put matter out of competition in a number of areas and processes.
Liquid helium is a quantum liquid, therefore its properties are determined by quantum effects. This was the reason that for a long time it was not possible to make it hard. Specific qualities did not allow it to harden even when absolute zero was reached.
It is also interesting that when a certain temperature is updated, a substance undergoes a so-called phase transition. One of the phases and is characterized by the above-mentioned superfluidity, that is, the ability to flow through narrow slots and capillaries without realizing friction (the state acquired by loss of viscosity).
Where is liquid helium used?
Helium, brought to the state of a liquid, is a highly effective coolant, thanks to which you can get an ultra-low temperature indicator. With that said, it is most often used:
– to obtain and maintain low and ultra-low temperatures (mostly in scientific research and experiments);
– when cooling superconducting magnets, popular parts of modern high-tech scientific, technical and medical equipment. For example, actual application in MRI devices important for medicine, in infrared and high-frequency radiation detectors, SQUID magnometers, scanning tunnel microscopes. One of the most striking examples of use is the charged particle accelerator Large Hadron Collider, in which tens of tons of this substance are used to cool down many superconducting magnets;
– in cryogenic electric machines;
– in cryostats (refrigerators) of dissolution.
Liquid helium is really a unique material, so it does not surprise the specificity of the application. Buy helium often need for medical and scientific fields. And this can be done quickly and easily on our website. Contact us!
