Search results
Results from the WOW.Com Content Network
A caesium atomic fountain used as part of an atomic clock. The caesium standard is a primary frequency standard in which the photon absorption by transitions between the two hyperfine ground states of caesium-133 atoms is used to control the output frequency.
Caesium (IUPAC spelling; [9] also spelled cesium in American English) is a chemical element; it has symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of 28.5 °C (83.3 °F; 301.6 K), which makes it one of only five elemental metals that are liquid at or near room temperature .
Caesium-134 is not produced via beta decay of other fission product nuclides of mass 134 since beta decay stops at stable 134 Xe. It is also not produced by nuclear weapons because 133 Cs is created by beta decay of original fission products only long after the nuclear explosion is over. The combined yield of 133 Cs and 134 Cs is given as 6. ...
The standard to be employed is the transition between the hyperfine levels F=4, M=0 and F=3, M=0 of the ground state / of the caesium 133 atom, unperturbed by external fields, and that the frequency of this transition is assigned the value 9192631770 hertz.
A unit of time is any particular time interval, used as a standard way of measuring or expressing duration. The base unit of time in the International System of Units (SI), and by extension most of the Western world, is the second, defined as about 9 billion oscillations of the caesium atom.
The All-Clad Factory Seconds Sale just started: Get up to 73% off All-Clad cookware
Alzheimer’s disease, the most common form of dementia affecting more than three million Americans a year, has proven difficult to diagnose in earlier stages. But detecting and treating the ...
Caesium-137 (137 55 Cs), cesium-137 (US), [7] or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons. Trace quantities also originate from spontaneous fission of uranium-238. It is ...