In this article,taking advantage of the special magnetic shieldings and the optimal coil design of a transportable Rb atomic fountain clock,the intensity distribution in space and the fluctuations with time of the qua...In this article,taking advantage of the special magnetic shieldings and the optimal coil design of a transportable Rb atomic fountain clock,the intensity distribution in space and the fluctuations with time of the quantization magnetic field in the Ramsey region were measured using the atomic magneton-sensitive transition method.In an approximately 310 mm long Ramsey region,a peak-to-peak magnetic field intensity of a 0.74 n T deviation in space and a 0.06 n T fluctuation with time were obtained.These results correspond to a second-order Zeeman frequency shift of approximately(2095.5±5.1)×10^(-17).This is an essential step in advancing the total frequency uncertainty of the fountain clock to the order of 10^(-17).展开更多
This article proposes a new physics package to enhance the frequency stability of the space cold atom clock with the advantages of a microgravity environment. Clock working processes, including atom cooling, atomic st...This article proposes a new physics package to enhance the frequency stability of the space cold atom clock with the advantages of a microgravity environment. Clock working processes, including atom cooling, atomic state preparation,microwave interrogation, and transition probability detection, are integrated into the cylindrical microwave cavity to achieve a high-performance and compact physics package for the space cold atom clock. We present the detailed design and ground-test results of the cold atom clock physics package in this article, which demonstrates a frequency stability of 1.2×10^(-12) τ^(-1/2) with a Ramsey linewidth of 12.5 Hz, and a better performance is predicted with a 1 Hz or a narrower Ramsey linewidth in microgravity environment. The miniaturized cold atom clock based on intracavity cooling has great potential for achieving space high-precision time-frequency reference in the future.展开更多
We designed, assembled, and tested a reliable laser system for ^(87)Rb cold atom fountain clocks. The laser system is divided into four modules according to function, which are convenient for installing, adjusting, ma...We designed, assembled, and tested a reliable laser system for ^(87)Rb cold atom fountain clocks. The laser system is divided into four modules according to function, which are convenient for installing, adjusting, maintaining, and replacing of the modules. In each functional module, all optical components are fixed on a baseplate with glue and screws, ensuring the system's structural stability. Mechanical stability was verified in a 6.11g RMS randomvibration test, where the change in output power before and after vibration was less than 5%. Thermal stability was realized by optimizing of the structure and appropriate selection of component materials of the modules through thermal simulation. In the laser splitting and output module, the change in laser power was less than 20% for each fiber in thermal cycles from 5℃ to 43℃. Finally,the functionality of the laser system was verified for a rubidium fountain clock.展开更多
基金supported by the National Natural Science Foundation of China(No.12004401)Ministry of Science and Technology of China(No.2013YQ09094304)。
文摘In this article,taking advantage of the special magnetic shieldings and the optimal coil design of a transportable Rb atomic fountain clock,the intensity distribution in space and the fluctuations with time of the quantization magnetic field in the Ramsey region were measured using the atomic magneton-sensitive transition method.In an approximately 310 mm long Ramsey region,a peak-to-peak magnetic field intensity of a 0.74 n T deviation in space and a 0.06 n T fluctuation with time were obtained.These results correspond to a second-order Zeeman frequency shift of approximately(2095.5±5.1)×10^(-17).This is an essential step in advancing the total frequency uncertainty of the fountain clock to the order of 10^(-17).
基金Project supported by the Space Application System of China Manned Space Programthe Youth Innovation Promotion Association,CAS。
文摘This article proposes a new physics package to enhance the frequency stability of the space cold atom clock with the advantages of a microgravity environment. Clock working processes, including atom cooling, atomic state preparation,microwave interrogation, and transition probability detection, are integrated into the cylindrical microwave cavity to achieve a high-performance and compact physics package for the space cold atom clock. We present the detailed design and ground-test results of the cold atom clock physics package in this article, which demonstrates a frequency stability of 1.2×10^(-12) τ^(-1/2) with a Ramsey linewidth of 12.5 Hz, and a better performance is predicted with a 1 Hz or a narrower Ramsey linewidth in microgravity environment. The miniaturized cold atom clock based on intracavity cooling has great potential for achieving space high-precision time-frequency reference in the future.
文摘We designed, assembled, and tested a reliable laser system for ^(87)Rb cold atom fountain clocks. The laser system is divided into four modules according to function, which are convenient for installing, adjusting, maintaining, and replacing of the modules. In each functional module, all optical components are fixed on a baseplate with glue and screws, ensuring the system's structural stability. Mechanical stability was verified in a 6.11g RMS randomvibration test, where the change in output power before and after vibration was less than 5%. Thermal stability was realized by optimizing of the structure and appropriate selection of component materials of the modules through thermal simulation. In the laser splitting and output module, the change in laser power was less than 20% for each fiber in thermal cycles from 5℃ to 43℃. Finally,the functionality of the laser system was verified for a rubidium fountain clock.
