Helium — otherusesHelium (He) is a colorless, odorless, tasteless, non toxic, inert monatomic chemical element that heads the noble gas group in the periodic table and whose atomic number is 2. Its boiling and melting points are the lowest among the… … Wikipedia
Helium-3 — This article is about the elemental isotope. For the record label Helium 3, see Muse or A E Records .infobox isotope background = #F99 isotope name = Helium 3 alternate names =Helium 3,He 3 symbol =He mass number =3 mass =3.016 num neutrons =1… … Wikipedia
Refrigerator — Fridge and Freezer redirect here. For other uses, see Fridge (disambiguation) and Freezer (disambiguation). For other uses, see Refrigerator (disambiguation). See also: Refrigeration A side by side refrigerator … Wikipedia
Dilution refrigerator — Gas control system for a helium dilution refrigerator A dilution refrigerator is a cryogenic device first proposed by Heinz London. Its refrigeration process uses a mixture of two isotopes of helium: helium 3 and helium 4. When cooled below… … Wikipedia
Liquid helium — Helium exists in liquid form only at very low temperatures. The boiling point and critical point depend on the isotope of the helium; see the table below for values. The density of liquid helium at its boiling point and 1 atm is approximately… … Wikipedia
Dry dilution refrigerator — A dry dilution system A dry (or cryogen free) dilution refrigerator is a type of dilution refrigerator that does not require the use of any external cryogens, in particular liquid helium, to operate. In the traditional design of a dilution… … Wikipedia
Pulse tube refrigerator — The Pulse tube cryocooler is a developing technology that emerged largely in the early 1980 s with a series of other innovations in the broader field of Thermoacoustics. In contrast with other cryocoolers (eg Stirling cryocooler and Gifford… … Wikipedia
Lambda point refrigerator — A lambda point refrigerator is a device used to cool liquid helium, typically around a superconducting magnet, from approximately 4.2 K to temperatures near the lambda point (approximately 2.17K), just above normal fluid helium (helium I) s… … Wikipedia
Isotopes of helium — Although there are eight known isotopes of helium (He) (standard atomic mass: 4.002602(2) u), only helium 3 (SimpleNuclide|Helium|3) and helium 4 (SimpleNuclide|Helium|4) are stable. In the Earth s atmosphere, there is one SimpleNuclide|Helium|3… … Wikipedia
Coldest temperature recorded on Earth — The coldest natural temperature ever recorded on Earth was −89 °C (−128°F) at the Russian Vostok Station in Antarctica July 21, 1983. [http://www.globe.gov/fsl/html/templ.cgi?archive atmos10271999 lang=en nav=6] Lower temperatures have been… … Wikipedia
