The worlds best clock, NIST-F1, has been improved over the past few years and now measures time and frequency more than twice as accurately as it did in 1999 when first used as a national standard, physicists at the National Institute of Standards and Technology (NIST) report.
The improved version of NIST-F1 would neither gain nor lose one second in 60 million years, according to a paper published online Sept. 13 by the journal Metrologia.* NIST-F1 uses a fountain-like movement of cesium atoms to determine the length of the second. The clock measures the natural oscillations of the atoms to produce more than 9 billion "ticks" per second. These results then contribute to the international group of atomic clocks that define the official world time. NIST-F1 has been formally evaluated 15 times since 1999; in its record performance, it measured the second with an uncertainty of 0.53 × 10-15
The improved accuracy is due largely to three factors, according to Tom Parker, leader of the NIST atomic standards research group. First, better lasers, software and other components have made the entire NIST-F1 system much more reliable and able to operate for longer periods of time. Second, the atoms in the cesium vapor are now spread out over a much larger volume of space, reducing the frequency shifts caused by interactions among the atoms. (The formerly round cloud of atoms is now shaped like a short cigar.) Third, scientists are now better able to control magnetic fields within the clock and quantify the corrections needed to compensate for their effects on the atoms.
Laura Ost | EurekAlert!
Scientists propose synestia, a new type of planetary object
23.05.2017 | University of California - Davis
Turmoil in sluggish electrons’ existence
23.05.2017 | Max-Planck-Institut für Quantenoptik
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.
In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...
Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...
23.05.2017 | Event News
22.05.2017 | Event News
17.05.2017 | Event News
23.05.2017 | Physics and Astronomy
23.05.2017 | Life Sciences
23.05.2017 | Medical Engineering