SOME ELECTROMECHANICAL METHODS FOR PRODUCING LOW FREQUENCIES FROM A PRIMARY FREQUENCY STANDARD

1949 ◽  
Vol 27f (2) ◽  
pp. 49-54 ◽  
Author(s):  
D. W. R. McKinley
Keyword(s):  
High Stability ◽  
Quartz Crystal ◽  
Primary Standard ◽  
Frequency Standard ◽  
Low Frequencies ◽  
Primary Frequency

Minor mechanical modifications to the clock motor of a quartz crystal primary standard of frequency simplify the problem of producing accurate low frequencies. Electromechanical gate circuits are used to provide pulses of high stability at repetition rates of 1, 10, 100, and 1000 pulses per second for stroboscopic and other applications.

OPTICAL CLOCKS AND FREQUENCY METROLOGY FOR SPACE

2007 ◽  
Vol 16 (12b) ◽  
pp. 2537-2540
Author(s):  
HUGH KLEIN
Keyword(s):  
European Space Agency ◽  
Frequency Standard ◽  
Optical Frequency ◽  
Fundamental Physics ◽  
Frequency Standards ◽  
Space Agency ◽  
Primary Frequency ◽  
Measurement Capabilities ◽  
Science Activities ◽  
Frequency Metrology

Optical frequency standards and femtosecond comb measurement capabilities now rival and in some cases exceed those of microwave devices, with further improvements anticipated. Opportunities are emerging for the application of highly stable and accurate optical frequency devices to fundamental physics space science activities, and the European Space Agency (ESA) has recently commissioned studies on different aspects of optical clocks in space. This paper highlights some examples, including the difficulty of comparing very accurate terrestrial clocks at different locations due to fluctuations of the geoid; by locating a primary frequency standard in space, one could avoid geoid-related gravitational redshifts.

The Navy's Primary Frequency Standard

1928 ◽  
Vol 16 (6) ◽  
pp. 778-793 ◽  
Author(s):  
R.H. Worrall ◽  
R.B. Owens
Keyword(s):  
Frequency Standard ◽  
Primary Frequency

Joint effort to commissioning a thermal cesium beam with optical pumping as primary frequency standard to Brazilian NMI

2014 ◽  
Author(s):  
Luiz Vicente Gomes Tarelho ◽  
Guilherme de Andrade Garcia ◽  
Antonio Carlos Baratto ◽  
Rodolfo Saboia Lima de Souza ◽  
Jair De Martin ◽  
...  
Keyword(s):  
Optical Pumping ◽  
Frequency Standard ◽  
Joint Effort ◽  
Primary Frequency

The optical frequency standard based on strontium cold atoms

2020 ◽  
pp. 22-27
Author(s):  
A. Y. Gribov ◽  
O. I. Berdasov ◽  
G. S. Belotelov ◽  
E. F. Stelmashenko ◽  
D. V. Sutyrin ◽  
...  
Keyword(s):  
Laser Cooling ◽  
Optical Lattice ◽  
Cold Atoms ◽  
Frequency Synthesizer ◽  
Primary Standard ◽  
Frequency Standard ◽  
Optical Frequency ◽  
Optical Frequency Standard ◽  
Laser Cooling And Trapping ◽  
Measuring Scheme

The results obtained during the development of an optical frequency standard, based on cold 87Sr atoms are presented. The parameters of experimental optical schemes developed for the realization of all stages of sequential laser cooling and trapping of 87Sr atoms into an optical lattice are described. Clock transition spectroscopy was successfully performed with a spectral transition linewidth of 12 Hz. A measuring scheme based on a femtosecond optical frequency synthesizer has been developed, which makes it possible to compare the optical standard with a hydrogen maser. The created optical frequency standard was included in the primary standard GET 1-2018.

An Optically Pumped Primary Frequency Standard

1989 ◽  
pp. 116-119 ◽  
Author(s):  
R. E. Drullinger ◽  
J. H. Shirley ◽  
D. J. Glaze ◽  
L. Hollberg
Keyword(s):  
Frequency Standard ◽  
Optically Pumped ◽  
Primary Frequency

scholarly journals Accuracy evaluation of the primary frequency standard NIST-7

Metrologia ◽  
2002 ◽  
Vol 39 (1) ◽  
pp. 123-123 ◽  
Author(s):  
J H Shirley ◽  
W D Lee ◽  
R E Drullinger
Keyword(s):  
Frequency Standard ◽  
Accuracy Evaluation ◽  
Primary Frequency
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