frequency standard fountain

An electronic sequence controller for the Cs fountain ...

The sequence control system for Cs atomic fountain clock is described in this paper. An electronic module to control the operational sequence of the Cesium (Cs) fountain frequency standard has been designed and developed. This control system consists of RF generation for AOMs and provides sequential control for cyclic operation of atomic fountain.

PROGRESS ON A PORTABLE RUBIDIUM FOUNTAIN …

A "transportable" atomic fountain, in this instance, means a physics package measuring roughly 1 m3 accompanied by a similarly sized electronics rack, such that the entire system would fit into a van or pickup truck. We will take advantage of the inherent frequency stability available in atomic fountains to

A Cesium fountain frequency standard: Preliminary results ...

A fountain frequency standard is now in operation at LPTF. A Ramsey resonance as narrow as 0.8 Hz has been obtained. A few days of continuous operation are routinely obtained. In closed loop operation the fountain frequency standard is continuously monitored against a H maser allowing an evaluation of the accuracy of the device.

(PDF) Progress on a miniature laser-cooled cesium fountain ...

PDF | The Time and Frequency Division of the National Institute of Standards and Technology (NIST) is developing a miniature laser-cooled Cs-fountain frequency standard. We anticipate that this ...

Frequency Biases in Pulsed Atomic Fountain Frequency ...

fountain frequency standards using traditional techniques such as operating at elevated microwave powers. I. INTRODUCTION As part of our work aimed at understanding the accuracy of NIST-F1, a laser-cooled cesium (Cs) fountain primary frequency standard at NIST, we have investigated the effect of spurious components in the microwave spectrum (spurs)

First international comparison of fountain primary ...

The comparison also includes a rubidium fountain frequency standard participating in the steering of TAI and enables a new absolute determination of the 87 Rb ground state hyperfine transition frequency with an uncertainty of . This paper is dedicated to the memory of André Clairon, who passed away on 24 December 2015, for his pioneering and ...

A cesium fountain frequency standard: preliminary results ...

Abstract: An atomic frequency standard based on a fountain of cold cesium atoms has been in operation in our laboratory for a few months. Ramsey fringes as narrow as 0.7 Hz have been obtained. The short-term frequency stability, measured against an H-maser, is 3 10/sup -13/ /spl tau//sup -1/2/, probably limited by the local oscillator frequency noise.

A Comparison of Cs Fountain Primary Frequency Standards

to give an overall fractional frequency difference and a total uncertainty of comparison. FOUNTAINS REPORTING TO THE BIPM . LPTF-FO1 (now SYRTE-FO1) was the first Cs fountain primary frequency standard to report to the BIPM in September 1995 with a fountain uncertainty of 3x10-15. There was also about an equivalent amount

The New PTB Caesium Fountain Clock CSF2

The caesium fountain frequency standard CSF1 has been operating at PTB since 1999. So far, CSF1 has contributed fifteen times to international atomic time (TAI) as a primary frequency standard. A relative short term instability of 2×10-13 (τ/1s)-1/2 and a relative uncertainty slightly below 10-15 have been obtained [1, 2]. However, further ...

NIM5 Cs fountain clock and its evaluation

The cesium fountain primary frequency standard NIM5 has been developed at the National Institute of Metrology in China. The NIM5 loads atoms in an optical molasses from the background Cs vapor ...

Frequency standard - Wikipedia

A frequency standard is a stable oscillator used for frequency calibration or reference. A frequency standard generates a fundamental frequency with a high degree of accuracy and precision.Harmonics of this fundamental frequency are used to provide reference points. Since time is the reciprocal of frequency, it is relatively easy to derive a time standard from a frequency standard.

A Comparison of Cs Fountain Primary Frequency Standards | NIST

Apr 23, 2008· There are currently 9 cesium fountain primary frequency standards reporting calibrations of TAI to the Bureau International des Poids et Measures (BIPM). An investigation has been carried out using data from the BIPM publication Circular T to evaluate the frequency offsets among these standards and ...

Frequency synthesis chain for the atomic fountain primary ...

Frequency synthesis chain for the atomic fountain primary frequency standard Abstract: The frequency noise of the local oscillator may degrade the long-term stability of high-stability frequency standard; a simple evaluation of this effect is performed to optimize the design of a synthesizer to be used in Cs atomic primary frequency standard.

Accurate rubidium atomic fountain frequency standard

a relative frequency inaccuracy of 8.6 ×10−18 [9]. On the other hand, interest in microwave fountain frequency standards is still very high. First, the SI second is still defined by the frequency of the ground state hyperfine transition of the 133Cs atom. Second, a microwave fountain standard is relatively simple: it can operate with just ...

Rubidium standard - Wikipedia

A rubidium standard or rubidium atomic clock is a frequency standard in which a specified hyperfine transition of electrons in rubidium-87 atoms is used to control the output frequency.It is the most inexpensive, compact, and widely produced atomic clock, used to control the frequency of television stations, cell phone base stations, in test equipment, and global navigation satellite systems ...

A SIMPLIFIED LASER AND OPTICS SYSTEM FOR LASER …

laser-cooled rubidium (Rb) atomic fountain frequency standard. This system uses DFB (Distributed Feedback) diode lasers and a frequency offset-locking scheme to generate the optical frequencies needed for laser-cooling, launching, post-cooling, and detection of Rb atoms.

Confessions Of A Reformed Frequency Standard Nut | Hackaday

Jan 17, 2018· Confessions Of A Reformed Frequency Standard Nut. ... I am a reformed frequency standard nut. ... I don't think there are any atomic fountain clocks in private hands. Yet.

A Portable Rubidium Fountain | NIST

Nov 15, 2010· We are developing a transportable laser-cooled rubidium (Rb) atomic fountain frequency standard. Over the last year we have built the Ramsey cavity and rubidium source oven and are preparing to assemble the physics package. We have also made numerous refinements to the laser package including ...

PROGRESS ON A PORTABLE RUBIDIUM FOUNTAIN …

optical trap (MOT), and the anticipated performance of our transportable Rb fountain frequency standard. INTRODUCTION . We have begun to develop a transportable laser-cooled Rb fountain microwave frequency standard. We consider "transportable" to mean a physics package of ~1 m3 accompanied by a similarly sized electronics rack.

CiteSeerX — fountain primary frequency standards

The fractional frequency uncertainties of some Cs fountains are now in the range of 4 × 10−16 to 5 × 10−16. The results of this investigation show that the standards agree well with each other. An overall estimate of the caesium frequency is made using the weighted mean of all the fountains.

Next-Generation Clock Increases Stability to 300 ...

"With the new rubidium fountain clock, we are going from the time standard of 1 to 2 nanoseconds down to 300 picoseconds," said Bill Bollwerk, Head of USNO Detachment Colorado. One nanosecond is equivalent to one billionth of a second, while a picosecond is equal to one trillionth of a second.

Session: P3FC-AFREQUENCY STANDARDS Chair: R. Wang JPL ...

FOUNTAIN FREQUENCY STANDARD D. G. ENZER* and W. M. KLIPSTEIN, Jet Propulsion Laboratory. Corresponding e-mail: [email protected] A laser-cooled Cesium fountain frequency standard has been developed to mirror the design of PARCS (Primary Atomic Reference Clock in Space) – an exper-

Preliminary Evaluation of the Cesium Fountain Primary ...

Abstract: We describe the preliminary evaluation of the frequency corrections and their uncertainty in the cesium fountain primary frequency standard (PFS) NMIJ-F2 under development at National Metrology Institute of Japan (NMIJ). In NMIJ-F2, cold atoms generated from a vapor-loaded optical molasses in the (001) configuration are optically pumped to the Zeeman sublevels of m F = 0 to increase ...

NPL Cs fountain frequency standards and the quest for the ...

The collisional frequency shift may vary significantly in the vicinity of the cancellation point (fig. ure. 1) and therefore a residual shift is measured and corrected during the normal operation of the fountain as frequency standard. The number of atoms is alternated by varying a microwave field amplitude in the

(PDF) Preliminary accuracy evaluation of a cesium fountain ...

A new primary frequency standard, the atomic caesium fountain CSF1, has been put into operation at the Physikalisch-Technische Bundesanstalt (PTB). 133Cs atoms are cooled in a magneto-optical trap ...

Long-term comparison of caesium fountain primary frequency ...

There are currently nine caesium fountain primary frequency standards regularly reporting calibrations of International Atomic Time to the Bureau International des Poids et Measures (BIPM).

Uncertainty evaluation of the continuous cesium fountain ...

Uncertainty evaluation of the continuous cesium fountain frequency standard FOCS-2 Abstract: The continuous atomic fountain primary frequency standard FOCS-2 is quite unique since all the atomic fountain clocks presently contributing to the international …

Time and Frequency Technology Related to the Operation …

Time and Frequency Technology Related to the Operation of a Cesium Fountain Primary Frequency Standard* Thomas E. Parker National Institute of Standards and Technology Time and Frequency Division 325 Broadway Boulder, CO 80305 USA Abstract The operation of a cesium fountain primary frequency standard is greatly facilitated by the