[1][2][3][4] This is a logical dividing line, since the normal boiling points of the so-called permanent gases (such as helium, hydrogen, neon, nitrogen, oxygen, and normal air) lie below 120 K, while the Freon refrigerants, hydrocarbons, and other common refrigerants have boiling points above 120 K.[5][6] Discovery of superconducting materials with critical temperatures significantly above the boiling point of nitrogen has provided new interest in reliable, low-cost methods of producing high-temperature cryogenic refrigeration.The field of cryogenics advanced during World War II when scientists found that metals frozen to low temperatures showed more resistance to wear.With a background in the heat treating industry, the Busch brothers founded a company in Detroit called CryoTech in 1966.Some chemical reactions, like those used to produce the active ingredients for the popular statin drugs, must occur at low temperatures of approximately −100 °C (−148 °F).Special cryogenic chemical reactors are used to remove reaction heat and provide a low temperature environment.LOX is also widely used with RP-1 kerosene, a non-cryogenic hydrocarbon, such as in the rockets built for the Soviet space program by Sergei Korolev.Russian aircraft manufacturer Tupolev developed a version of its popular design Tu-154 with a cryogenic fuel system, known as the Tu-155.
This is a diagram of an infrared space telescope that needs a cold mirror and instruments. One instrument needs to be even colder, and it has a cryocooler. The instrument is in region 1 and its cryocooler is in region 3 in a warmer region of the spacecraft (see
MIRI (Mid-Infrared Instrument)
or
James Webb Space Telescope
).
A medium-sized
dewar
is being filled with liquid nitrogen by a larger cryogenic storage tank.