What is cryogenics


Cryogenics, Cryogenics (from ancient Greek κρύος [cryos] “Frost, ice”) or low-temperature technology is the technology for generating low temperatures (Joule-Thomson effect) and for using physical effects at low temperatures (liquefaction and separation of gases). Cryogenic technology covers the temperature range below about -150 ° C. Technically easily accessible temperatures of 77.4 K (-195.8 ° C), the boiling point of nitrogen, 20.4 K (with hydrogen), and 4.2 K (with helium). Liquid nitrogen or liquid helium can be conveniently stored and transported in Dewar flasks for cooling purposes. Lower temperatures can be achieved by reducing the pressure and the associated change in the boiling point. With helium you can get down to about 1 K, with the (expensive) isotope 3He even down to 1 mK. Liquid helium is most widely used to cool the superconducting windings of electromagnets.

Applications of cryogenics can be found in

  • Energy technology (nuclear fusion reactors)
  • High energy physics (particle accelerator)
  • Vacuum technology (cryopump)
  • Energy technology (SMES energy storage, liquid hydrogen fuel)
  • Rocket technology (e.g. pumps for liquid oxygen)
  • Measurement technology (SQUIDs, detectors, NMR)
  • Cryobiology (engl.Cryobiology)
  • Process engineering (liquefaction of gases, low-temperature rectification, recycling)
  • Production of technical gases
  • Petrochemical, natural gas industry (natural gas liquefaction)
  • Food industry (shock freezing)
  • Energy recovery technology
  • Electrical engineering, electronics
  • Medicine: MRI, cryosurgery, extraction of medical gases
  • Funeral services, promession
  • Conservation, cryopreservation
  • Cryonics or cryostasis

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See also