频率稳定度是评价相干布局囚禁(CPT)原子钟性能的重要指标,而原子气室内部缓冲气体的种类及其气压比是影响CPT原子钟频率稳定度的主要因素。选用Ar与N₂为缓冲气体,从理论上对其温度频移特性进行仿真分析,并在不同缓冲气体气压比例的条件下实验测量了CPT原子钟的温度频移特性。根据理论与实验结果确定了原子气室内部缓冲气体最佳的比例,并给出了与之对应的最小温度频移工作点。研究结果对设计CPT原子钟原子气室内部的缓冲气体气压比及其工作温度具有借鉴作用。

Frequency stability is an important indicator to evaluate the performance of a coherent population trapping (CPT) atomic clock, and the type and pressure ratios of the buffer gas compositions inside an atomic vapor cell are main factors influencing frequency stability. In this study, the temperature frequency shift caused by buffer gas compositions, i.e., Ar and N2, was simulated and analyzed theoretically, and the temperature shifts caused by different pressure ratios of buffer gas compositions were tested experimentally. The optimal ratio of buffer gas compositions in the atomic vapor cell was determined based on the theoretical and experimental results, and the corresponding operation point for the minimum temperature frequency shift was found. The research results provide a valuable reference for selecting the pressure ratio of buffer gas compositions and the operation temperature of the atomic vapor cell for a CPT atomic clock.