A cold shield is a device to protect an object from unwanted heating by thermal radiation or light. Usually it is a cooled object with low absorption and high reflectivity.
It can be found in Molecular beam epitaxy chambers to protect the growth areas from thermal radiation from hot sources. In cryostats, a radiation shield protects a sample from infrared radiation. An infrared detector is protected from thermal background radiation outside its optical field of view. These devices are usually cooled to the same temperature as the detector.
Cold shields are typically used in IR optical devices for military, scientific and industrial applications to protect IR sensors from stray IR radiation (lowering noise figures). Most coldshield applications require near instantaneous cooling, the low mass of the structure is very important.
Famous quotes containing the words cold and/or shield:
“That cold accretion called the world, which, so terrible in the mass, is so unformidable, even pitiable, in its units.”
—Thomas Hardy (1840–1928)
“Vice is its own reward. It is virtue which, if it is to be marketed with consumer appeal, must carry Green Shield stamps.”
—Quentin Crisp (b. 1908)