A locking method for cesium beam atomic clock

Abstract

The invention discloses a locking method for a cesium beam atomic clock. The locking method includes: step 1 microwave frequency modulation: modulate the microwave frequency; step 2 microwave frequency scanning: input microwave into a cesium beam tube to obtain atomic signals; step 3 frequency error Signal demodulation: demodulate the atomic signal with a frequency modulated signal and low-pass filter to generate a frequency error signal e ω (t); set the microwave frequency at e ω (t) At the maximum point, change the microwave power b and record the error signal e ω (t) The microwave power b when taking the maximum value 1 ; Step 4 microwave power modulation: at the microwave power b 1 The microwave power is modulated near the point; Step 5 microwave frequency-power joint locking: the error signal e ω (t) Perform proportional-integral-derivative (PID) processing and feed back to the microwave frequency setting terminal to achieve frequency locking; ω (t) Demodulate and low-pass filter the power modulation signal to obtain a microwave power error signal, and perform PID processing on the microwave power error signal and feed it back to the microwave power control terminal to achieve power closed-loop locking.

Description

technical field [0001] The invention relates to the field of atomic frequency standards, in particular to a locking method for a cesium beam atomic clock. Background technique [0002] An atomic clock is a timekeeping device that uses the transitions of atoms as a standard. It is currently the most accurate time and frequency standard, so its application range is extremely wide: from precise basic scientific measurements, such as the determination of physical constants, theoretical physics verification, to engineering applications that directly serve people's daily production and life, such as global navigation satellites system etc. The cesium beam atomic clock has the characteristics of high accuracy and good long-term stability. It is the core equipment for establishing and maintaining a high-precision and high-stability timekeeping system. application. [0003] The long-term frequency stability of cesium beam atomic clocks is affected by various frequency shift factor...

AI Technical Summary

Problems solved by technology

[0005] First, ideally, the relationship between the microwave power and the amplitude of the cesium beam tube output signal is as follows figure 2 , but in fact, because the influence of adjacent transition lines will increase under high microwave power, the signal amplitude will be larger when the microwave power increases, such as figure 2 , so microwave power may lose lock when using traditional methods for locking;

[0006] Second, the stability of the cesium atomic clock is positively correlated with the amplitude of the frequency-locking error signal. Usually, the maximum value of the signal and the maximum value of the error signal are not at the same microwave power point, so the traditional method is difficult to achieve the best performance index of atomic clock stability;

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