The RAFS (Rubidium Atomic Frequency Standard) is a high-performance, radiation-resistant 10 MHz frequency standard based on the atomic reference provided by the Rb87 isotope’s spectrum absorption line.
The Rubidium Frequency Standard regulates the frequency of television stations, cell phone base stations, test equipment, and satellite navigation systems like GPS.
The device fulfills a variety of communication, synchronization, and instrumentation requirements.
Please read through for some information on the rubidium frequency standard.
How Does Rubidium Frequency Standard Work?
A chamber containing rubidium gas is present in the physics package, and the level of this light is detected by shining a light through the gas. Microwave energy at the gas’s transition frequency excites the rubidium gas.
Rubidium and Atomic Clocks
An atomic clock is a device that utilizes an atomic resonance to produce a highly-stable frequency suitable as a frequency reference and for precise timekeeping.
The simplest and smallest of all atomic clocks, rubidium atomic clocks use a glass cell of rubidium gas that changes its absorption of light at the optical rubidium frequency when the surrounding microwave frequency is perfect.
Why Use an Atomic Clock
Most atomic clocks are utilized as sources of exact time rather than as frequency standards per se. A frequency source error substantially below the 1×10-11 level is necessary to maintain time to the microsecond level for a few days, which is a problematic condition for an ovenized quartz crystal oscillator3.
Therefore, an RFS may be the most sensible option. Cellular telephony, geophysical data logging, GPS rapid acquisition/robustness, and frequency hopping radios are common RFS timing applications. High-speed rubidium frequency standard clocks have replaced the preferred gadget on GPS satellites.
History of Rubidium Frequency Standard
Due to its blend of use and performance, the rubidium frequency standard has roughly become the dominant type of atomic clock over the previous 60 years. Although the fundamentals of its design haven’t changed much in that time, it has made great strides in adapting to a variety of demanding space-qualified requirements, challenging military applications, and low-cost commercial applications.
Previous RFS Historical Reviews
Arthur McCoubrey published the first historical analysis of the rubidium frequency standard in 1966. It was published at a relatively early point in the development of rubidium frequency standards and included a brief explanation of the standards’ performance, their underlying physical principles, and various illustrations of RFS products made by General Technology and Varian. When the Frequency Control Symposium celebrated its 50th anniversary in 1996, McCoubrey conducted a second survey 30 years later.
How was Rubidium Discovered?
Lepidolite was found to behave strangely when it was discovered in the 1760s. Since it foamed when tossed upon a lump of burning coal and eventually became glass-like, it appeared to contain substances besides the known elements lithium and potassium. The ore was dissolved in acid in 1861 by Kirchhoff and Bunsen of the University of Heidelberg in Germany. They precipitated the potassium it contained and the suspected more substantial alkal威而鋼
i metal component.
They carefully removed the more soluble potassium from the residue by gently washing it in hot water, and then they examined the remaining material’s atomic spectrum. Upon completion of the precipitation, they confirmed the finding of a new element called rubidium by spotting two lines of vivid ruby-red hue that had never been seen before.
