New super-accurate atomic clock developed

A US government agency has developed a new atomic clock that would neither gain nor lose one second in about 300 million years, making it three times as accurate as its predecessor.
The US Department of Commerce's National Institute of Standards and Technology (NIST) launched the new atomic clock, called NIST-F2, to serve as a new US civilian time and frequency standard, along with the current NIST-F1 standard.
NIST-F2 would neither gain nor lose one second in about 300 million years, making it about three times as accurate as NIST-F1, which has served as the standard since 1999, NIST said.

Both clocks use a "fountain" of cesium atoms to determine the exact length of a second.
NIST scientists recently reported the first official performance data for NIST-F2, which has been under development for a decade, to the International Bureau of Weights and Measures (BIPM), located near Paris, France.
That agency collates data from atomic clocks around the world to produce Coordinated Universal Time (UTC), the international standard of time.

According to BIPM data, NIST-F2 is now the world's most accurate time standard, NIST said in a statement.
Many everyday technologies, such as cellular telephones, Global Positioning System (GPS) satellite receivers, and the electric power grid, rely on the high accuracy of atomic clocks, NIST said.

Historically, improved timekeeping has consistently led to technology improvements and innovation.
"If we've learned anything in the last 60 years of building atomic clocks, we've learned that every time we build a better clock, somebody comes up with a use for it that you couldn't have foreseen," said NIST physicist Steven Jefferts, lead designer of NIST-F2.
For now, NIST plans to simultaneously operate both NIST-F1 and NIST-F2.
Long-term comparisons of the two clocks will help NIST scientists continue to improve both clocks as they serve as US standards for civilian time.
Both NIST-F1 and NIST-F2 measure the frequency of a particular transition in the cesium atom - which is 9,192,631,770 vibrations per second, and is used to define the second, the international (SI) unit of time.

The key operational difference is that F1 operates near room temperature (about 27 degrees Celsius) whereas the atoms in F2 are shielded within a much colder environment (at minus 193 degrees Celsius).
This cooling dramatically lowers the background radiation and thus reduces some of the very small measurement errors that must be corrected in NIST-F1.