Symmetricom Chip Scale Atomic Clock (CSAC)
name: label: maker
content: Symmetricom, Incorporated
notes: label: Description
content: Chip-scale atomic clocks (CSAC) have components comparable in size to the integrated circuits (“chips”) used in modern electronic equipment. They were first developed by the Defense Advanced Research Projects Agency (DARPA) and the National Institute of Standards and Technology (NIST) in 2004. The first commercial version is this cesium CSAC with model number SA.45s, produced by Symmetricom, Inc., in Beverley, Mass., and sold beginning in 2011. Its “physics package” (the set of components that generate the cesium frequency) occupies less than 1 cubic centimeter, thousands of times smaller and lighter than the beam tube of a conventional cesium atomic clock and operates on very different principles. Furthermore, the energy consumption is much less, making extended operation on battery power feasible. Developing such a small clock required many innovations in several disciplines, including semiconductor laser technology, silicon processing, vacuum-packing and firmware algorithms. Its portability and low energy consumption have made possible many new applications, such as geophysical sensors, backpack jammers for improvised explosive devices, backpack military radios, unmanned aerial vehicles (drones) and military GPS receivers, but, as of 2013, it has not yet been used in space.
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Modern Physics
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content: Time and Navigation
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content: Measuring & Mapping
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 2011.0207.01
label: accession number
content: 2011.0207
label: catalog number
content: 2011.0207.01
objectType: label: Object Name
content: atomic clock
physicalDescription: label: Physical Description
content: metal (clock material)
label: Physical Description
content: cardboard, foam (box material)
label: Measurements
content: clock: 1 in x 2 in x 1 3/4 in; 2.54 cm x 5.08 cm x 4.445 cm
label: Measurements
content: box: 1 1/2 in x 4 3/4 in x 4 1/4 in; 3.81 cm x 12.065 cm x 10.795 cm
label: Measurements
content: overall-box: 1 1/8 in x 4 3/8 in x 3 7/8 in; 2.8575 cm x 11.1125 cm x 9.8425 cm
label: Measurements
content: overall-clock: 1/2 in x 1 5/8 in x 1 3/8 in; 1.27 cm x 4.1275 cm x 3.4925 cm