a device used for the temporary storage of liquid nitrogen

an insulated container used to store liquefied gases

a sophisticated Thermos bottle for holding cryogenic liquids

a vessel isolated by vacuum, highly reflecting walls and radiation screens used to achieve and maintain cryogenic temperatures

The Dewar is a thermos-like container used to store protein samples and keep them frozen until the liquid nitrogen thaws.

See cryostat.

CCDs operate at their optimum when cold. Dewars are made for just that purpose. Astronomers want only optimized equipment to collect the most light possible from distant objects. For the CCD to run at its best, it needs to be cold--as cold as liquid nitrogen (77 Kelvin/-321°F/-196°C). CCDs generate electrons just from being warm (by warm, we mean room temperature), without exposure to light. Also, the chamber where the CCD resides needs to be under vacuum. The CCD will be below the freezing point of water, once cooled. Water vapor in the atmosphere would condense on the surface of the device (frost!), if the atmospheric air was not removed, and affect the images.

An insulated container for holding liquified gases, i.e., cryogens. May also be called a cryostat.

thermos container to retain liquid gases, such as helium, at low temperatures (after Sir Janner Dewar).

Pressure vessel created to sustain cryogenic temperatures.

A vacuum walled container for thermally isolating the contents from the outside. Dewars are used for holding and transporting cryogenic liquids.