Locking method of cesium beam atomic clock

Abstract

The invention discloses a locking method of a cesium-beam atomic clock. The locking method comprises the following steps: step 1, microwave frequency modulation: modulating microwave frequency; 2, microwave frequency scanning, wherein microwaves are input into the cesium-beam tube to obtain atomic signals; step 3, frequency error signal demodulation: using the frequency modulation signal to demodulate the atomic signal and performing low-pass filtering to generate a frequency error signal e omega (t); setting the microwave frequency at the maximum position of e omega (t), changing the microwave power b, and recording the microwave power b1 when the error signal e omega (t) is the maximum value; step 4, microwave power modulation: the microwave power is modulated near the microwave power b1 point; 5, microwave frequency-power combined locking: carrying out proportional-integral-differential (PID) processing on the error signal e omega (t), and feeding back the processed signal to a microwave frequency setting end to realize frequency locking; and demodulating the e omega (t) by using a power modulation signal, performing low-pass filtering to obtain a microwave power error signal, performing PID processing on the microwave power error signal, and feeding back the processed signal to a microwave power control end to realize 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 long-term stability. It is the core equipment for establishing and maintaining high-precision and high-stability timekeeping systems. It has extensive applications in the fields of timekeeping, time service, communication, electric power, and time-frequency measurement. ...

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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