Small Cesium Atomic Fountain Clock for Time Keeping System
JIN Shuanghao1,2,LIN Pingwei2,3,RU Ning2,3,MA Yanning2,3,JIANG Wensong1,LUO Zai1
1. College of Metrology & Measurement Engineering, China Jiliang University, Hangzhou, Zhejiang 310018,China
2. National Institute of Metrology, Beijing 100029, China
3. Innovation Center for Advanced Traceability Technology, Beijing 102299, China
Abstract：The small cesium atomic fountain clock has excellent long-term stability performance,and has the advantages of high reliability,automation,miniaturization and mobility.It has the potential to be realized as a mobile timekeeping clock in a vehicle-mounted form.It can be used as a node clock in a timekeeping atomic clock group to ensure accurate frequency and time signals.The developed small cesium atomic fountain clock NIM-TF3 has a frequency stability of 2.7×10-13@s and 5.3×10-15@one day.NIM-TF3 adopts an integrated laser system and integrated electronic control system,which can achieve long-term automatic continuous operation.It integrates the developed small microwave frequency synthesizer with the physical system,which significantly reduces the system volume and enhances the overall stability.and reliability.In addition,through evaluation,it was found that the second-order Zeeman relative frequency shift caused by uneven distribution of the C field is 7.3×10-14,and the uncertainty is 0.2×10-15.The overall volume of NIM-TF3 is less than 0.7m3,and it has the potential to become a vehicle-mounted fountain clock.
CUTLER L S. Fifty years of commercial caesium clocks [J]. Metrologia, 2005, 42(3): S90-S99.
LI T C, LI M S, LIN P W, et al. NIM4~#Laser-cooled cesium atomic fountain clock—a new generation of national time and frequency benchmark [J]. Acta Metrologica Sinica, 2004,25(3): 193-197.
[3]
SZYMANIEC K, PARK S E, MARRA G, et al. First accuracy evaluation of the NPL-CsF2 primary frequency standard [J]. Metrologia, 2010, 47(4): 363-376.
[6]
HEAVNER T P, JEFFERTS S R, DONLEY E A, et al. NIST-F1: recent improvements and accuracy evaluations [J]. Metrologia, 2005, 42(5): 411-422.
[8]
PARTHEY C G, MATVEEV A, ALNIS J, et al. Precision Measurement of the Hydrogen-Deuterium 1 S-2 S Isotope Shift [J]. Physical Review Letters, 2010, 104(23): 233001.
[10]
BAUCH A. Caesium atomic clocks: function, performance and applications [J]. Measurement Science and Technology, 2003, 14(8): 1159-1173.
[13]
CHAPELET F, GUENA J, ROVERA D, et al. Comparisons between 3 fountain clocks at LNE-SYRTE[C]// 2007 IEEE International Frequency Control Symposium Joint with the 21st European Frequency and Time Forum. Geneva, Switzerland, 2007: 467-472.
[15]
BURT E, SWANSON T, EKSTROM C. Cesium fountain development at USNO[C]// Proceedings of the 1999 Joint Meeting of the European Frequency and Time Forum and the IEEE International Frequency Control Symposium. Besancon, France, 1999, 1: 20-23.
LI T C. From the unit of length meter to the unit of time second: frequency-stabilized laser-femtosecond optical comb-cesium atomic fountain clock-optical clock [J]. Acta Metrologica Sinica, 2006, 27(1): 1-6.
[4]
BEATTIE S, JIAN B, ALCOCK J, et al. First accuracy evaluation of the NRC-FCs2 primary frequency standard [J]. Metrologia, 2020, 57(3): 035010.
[12]
RAMSEY N F. Experiments with Separated Oscillatory Fields and Hydrogen Masers [J]. Science, 1990, 248(4963): 1612-1619.
BURT E, SWANSON T, EKSTROM C. Preliminary results from the USNO cesium fountain atomic clock[C]//Conference on Precision Electromagnetic Measurements. Sydney, Australia, 2000: 672-675.
ZHANG H, WANG X L, LIU D D, et al. A study of laser collimator cylinders for cold atomic fountains [J]. Journal of Time and Frequency, 2022, 45(2): 115-123.
PARTHEY C G, MATVEEV A, ALNIS J, et al. Improved Measurement of the Hydrogen 1 S-2 S Transition Frequency [J]. Physical Review Letters, 2011, 107(20): 203001.
[9]
REYNAUD S, SALOMON C, WOLF P. Testing General Relativity with Atomic Clocks [J]. Space Science Reviews, 2009, 148(1-4): 233-247.
LIU H K, LIU K, HAN L, et al. Measurement and calculation of C field of cesium fountain clock [J]. Acta Metrologica Sinica, 2023, 44(2): 258-264.
MIN J C, JIN S H, JIANG W S, et al. Atomic air cell relaxation rate measurement based on atomic Rabi resonance [J]. Acta Metrologica Sinica, 2023, 44(4): 604-608.
LIU S, LIN P W, LIU N F. Development of DDS for suppressing microwave leakage frequency shift [J]. Modern Measurement and Laboratory Management, 2010, 18(3): 3-7.
2024, Vol. 45 
