cesium fountain

cesium fountain

[¦sēz·ē·əm ′fau̇nt·ən]
(atomic physics)
A device for performing highly accurate frequency measurements, in which cesium atoms are cooled and trapped by pairs of counterpropagating tuned laser beams and are thrown upward by shifting the frequency of the vertical lasers; they are further cooled and placed in one of the hyperfine states, and then pass through a microwave field region before falling into a detection region.
References in periodicals archive ?
Currently, cesium fountain clocks NIST-F1 and NIST-F2 are operated for about one week each month to calibrate NIST time scales, arrays of hydrogen masersmicrowave versions of lasersmaintaining official U.
Technicians must average the current US civilian time standard, the NIST-F1 cesium fountain clock, for about 400,000 seconds (about five days) to obtain its best performance.
clock keeps perfect time Scientists have determined that the cesium fountain clock used by the U.
Washington, August 12 (ANI): Scientists at the National Institute of Standards and Technology (NIST) have said that an experimental atomic clock based on ytterbium atoms is about four times more accurate than it was several years ago, giving it a precision comparable to that of the NIST-F1 cesium fountain clock, the civilian time standard of the US.
The modulation concept was tested on the NIST cesium fountain clock, NIST-F1, and found to work so well that it has become the preferred mode of operation.
Contract award: design, fabrication, and testing atomic frequency standard based on the cesium fountain structure - 2 pieces.
A cesium fountain consists of several key elements that need to be built independently and then make their integration:
The atom ball in the LPTF cesium fountain is formed either using a magneto-optical trap (MOT) or optical-molasses (26).
The NIST cesium fountain is described in greater detail elsewhere (27) and only a short overview is given here.
Atomic cesium is an important species that has been utilized in numerous cooling and trapping experiments; for example, laser-cooled cesium forms the basis of the new NIST-F1 cesium fountain atomic clock.
Contrary to previous expectations, the new model predicts that the collisional shift in a cesium fountain clock could be greatly reduced if the clock could be operated at a much lower temperature, in the range of 50 nK.
One of the awards goes to the most recent in NIST's 51 year long line of ever-more-precise atomic clocks, the NIST-FI cesium fountain clock, unveiled in December 1999.