Temperature-immune microwave resonators for cold atomic fountain clocks

Abstract

The invention relates to a temperature-immune microwave resonator for a cold atomic fountain clock. The cover, the lower end cover and the vertical cylinder together form a resonant cavity; the cylinder wall of the vertical cylinder has an even number of coupling holes along the horizontal center plane of the resonant cavity, and the coupling holes are distributed symmetrically along the radial direction of the resonant cavity; the vertical cylinder, the upper end cover The first material, the second material and the third material are selected for the lower end cap and the lower end cap respectively, and the thermal expansion coefficient of the first material is smaller than that of the second material or the third material. In the present invention, the resonant frequency change caused by the radius of the resonant cavity induced by temperature fluctuations is completely compensated by the resonant frequency change caused by the height of the resonant cavity induced by temperature fluctuations, so that the resonant frequency of the microwave resonator is completely immune to ambient temperature fluctuations, thereby The fountain clock is not sensitive to ambient temperature fluctuations, which is very conducive to the transport and commercial application of the fountain clock.

Description

technical field [0001] The invention belongs to the technical field of atomic frequency standards, in particular to a temperature-immune microwave resonator for cold atomic fountain clocks. Background technique [0002] As a time-frequency reference device, the cold atomic fountain clock outputs a frequency standard signal with ultra-high long-term frequency stability, frequency reproducibility and frequency uncertainty. It plays an important role in the comparison and determination of the fundamental constants of physics. The portability and commercial application of the whole machine has become a hot spot in the research of cold atomic fountain clocks, and the sensitivity to ambient temperature fluctuations is its core limiting factor. [0003] As the core device of the cold atomic fountain clock, the microwave resonator provides a place for the transition between the microwave radiation field and the two hyperfine energy levels of the atomic ground state in the process o...

AI Technical Summary

Problems solved by technology

[0006] Some embodiments of the present invention propose a temperature-immune microwave resonator for cold atomic fountain clocks, solving the problem that the vertical cylinder, upper end cover and lower end cover of microwave resonators in the prior art all use oxygen-free copper or aluminum materials , the resonant frequency of the microwave resonator is sensitive to the ambient temperature, which makes the fountain clock sensitive to the fluctuation of the ambient temperature, which is not conducive to the technical problems of transportability and commercial application

Images