Cryogenics

Among the many important industrial applications of cryogenics are the large-scale production of oxygen and nitrogen from air. The oxygen can be used in a variety of ways, for example, in rocket engines, for cutting and welding torches, for supporting life in space and deep-sea vehicles, and for blast furnace operations. The nitrogen goes into the making of ammonia for fertilizers, and it is used to prepare frozen foods by cooling them rapidly enough to prevent destruction of cell tissues. It can also serve as a refrigerant and for transporting frozen foods.

Cryogenics has also made possible the commercial transportation of liquefied natural gas. Without cryogenics, nuclear research would lack liquid hydrogen and helium for use in particle detectors and for the powerful electromagnets needed in large particle accelerators. Such magnets are also being used in nuclear fusion research. Infrared devices, masers, and lasers can employ cryogenic temperatures, as well. Cryogenic cooling is often used in space telescopes that observe objects in infrared and microwave wavelengths. More efficient and compact cryocoolers allow cryogenic temperatures to be used in an increasing variety of military, medical, scientific, civilian, and commercial applications, including infrared sensors, superconducting electronics, and magnetic levitation trains.

Bose-Einstein condensates and fermionic condensates are useful for scientific research into quantum phenomena such as superfluidity and superconductivity. Such unusual states of matter may also lead to quantum computing and devices such as atomic lasers. Chemical reactions and other properties of molecules can also be studied at cryogenic temperatures.

Cryogenic temperatures are also used in cryobiology—the study of life and life processes at very low temperatures. Cryobiology includes cold temperatures used in medicine and surgery, as well as the cryogenic preservation of biological and medical materials.