Search

In this paper, detailed geometry of the detection chamber, configuration of detection probe laser beams, data acquisition and processing techniques of the cold atoms in Cs atomic fountain primary standard at NPL, India has been discussed. The S/N ratio in the detected atom count was too low to make a valid estimate of signal. By implementing an efficient design of detection hardware (especially changing photodiode with lower junction capacitance) and software, the S/N ratio in NPLI-CsF1 has been improved significantly (~ 10 times). Details of the detection hardware and software used for better processing of the signal are given in this paper. This paper also depicts the precise computer control for data processing and the improvements in signal to noise ratio in the context of fountain operation. [ABSTRACT FROM AUTHOR]

CSIR-NPL, India (NPLI) has developed its first Cesium atomic fountain (NPLI-CsF1). The indigenously developed fountain frequency standard is now fully operational and its frequency is now being evaluated along with all systematic and statistical uncertainties. Seven frequency evaluations have been recently conducted to estimate fountain frequency with respect to UTC (Coordinate Universal Time). The fountain frequency is compared with the Hydrogen MASER frequency which is contributing to UTC and hence fountain frequency is evaluated with respect to the UTC The fountain frequency is stable to few parts in 10 at <1 day averaging time. [ABSTRACT FROM AUTHOR]

Frequency corresponding to the energy difference between designated levels of an atom provides precise reference for making a universally accurate clock. Since the middle of the 20th century till now, there have been tremendous efforts in the field of atomic clocks making time the most accurately measured physical quantity. National Physical Laboratory India (NPLI) is the nation's timekeeper and is developing an atomic fountain clock which will be a primary frequency standard. The fountain is currently operational and is at the stage of complete frequency evaluation. In this paper, a brief review on atomic time along with some of the recent results from the fountain clock will be discussed. [ABSTRACT FROM AUTHOR]