The atomic frequency
data and total number of tetrahedra generated by tessellating the totality of the atomic coordinate data in the 1417 PDB structure files (hydrogen atoms and water molecules excluded, as discussed in Methods), after filtering out edges longer than 12 [Angstrom], are provided in Table 7.
The precise realization of the SI second that we benefit from today was made possible by the development of atomic frequency
standards and clocks; devices that fundamentally changed the way that time is measured and kept.
Allan, "Statistics of Atomic Frequency
Standards," Proceedings of the IEEE, vol.
Government-sponsored effort to develop a low-power, miniature, affordable precision atomic frequency
The NPE consists of several transmitter units and the mission data unit, both designed and built by ITT; Atomic Frequency
Time Standard; passive RF components and various harnesses and cables.
Designed for ease of integration into frequency and timing systems, the 8130A offers a smaller size MIL atomic frequency
"Instead of measuring the distance an atom falls in a certain amount of time," Chu explained, "our atomic gravity meter measures the change in velocity during a given time by measuring the Doppler shift of a very well-known atomic frequency
." The researchers expect to push the technique to 1 part in 10 billion in the near future, making the technique about 1000 times more accurate than any other, Chu said.
If the RF oscillator is phase-locked to an atomic frequency
standard, the comb will form an accurate frequency ruler covering the entire near infrared region from 1100 nm to 2200 nm.
The average pitch obtained by the process, nominally half the laser wavelength, is simply traceable with small uncertainty to an atomic frequency
and hence can be known with very high accuracy.