Newsletter | Vol 13 - June 2021

Markets and Applications for Cryogenics


Some properties, such as electrical conductivity and thermal conductivity, can change by several orders of magnitude when cooled from room temperature to 4 K or below.

Benefits of Cryogenic Temperatures
  • Preservation of biological material and food
  • High fluid densities ? liquified gases
  • Superconductivity and superfluidity ? no resistance to the flow of electricity and no resistance to the flow of the fluid
  • Reduction of thermal noise
  • Low vapor pressures
  • Temporary and permanent property/phase changes
  • Tissue destruction


Liquify Gases

Common permanent gases change from gas to liquid at cryogenic temperatures (a permanent gas is one whose critical temperature is far below room temperature). These liquids are known as cryogenic liquids. Temperatures these gases liquify are listed below:

  • Methane 112 K
  • Oxygen 90 K
  • Nitrogen 77 K
  • Hydrogen 20 K
  • Helium 4.2 K


Space applications that rely on cryogenic materials and technology include:

  • Antennas
  • Rockets
  • Satellites
  • Space craft
  • Sensors
  • Astrophysics and space telescopes


The superconducting magnet coils in most magnetic resonance imaging (MRI) systems require temperatures of 4 K with GM cryocoolers that condense the boil off from a bath of liquid helium. An electromagnet wound with a wire of extremely low electrical resistance can produce extremely high magnetic fields with no generation of heat and no consumption of power once the field is established and the metal remains cold. These metals, typically niobium alloys cooled to 4.2 K are used for the magnets of MRI systems. Copper electromagnets are impractical because of the massive heat generated and the cooling systems required to remove the heat. MRI is the largest commercial application of superconductivity (22,000 units worldwide and 1000+ added each year). About 100 tons/yr of NbTi alloy are required to produce the superconducting magnets.


Infrared sensors are used for military night vision equipment which require cooling to 80-150 K. The Stirling-type pulse tube cryocoolers are used for this application. Night vision relies on detecting thermally radiated electromagnetic spectra. There have been spinoffs of this cooled infrared technology for police, rescue and security operations.

Industrial and Transportation

Magnetic levitation requires superconductivity and superconducting magnets. Monorail trains rely on this technology.

Other industrial applications include:

  • Furnace atmospheres
  • Heat treating
  • Cooling detectors
  • Chemical processing
  • Scanning electronic microscopes


Superconducting electronics or power systems utilize regenerative cryocoolers.