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:
“Massa’s in de cold, cold ground.”
—Stephen Collins Foster (1826–1864)
“The lichen on the rocks is a rude and simple shield which beginning and imperfect Nature suspended there. Still hangs her wrinkled trophy.”
—Henry David Thoreau (1817–1862)