原子吸收光谱对碱金属原子蒸气密度与压强的测量方法

发布时间：2018-06-14 20:31

本文选题：原子吸收光谱 + 原子密度　；参考：《光谱学与光谱分析》2015年02期

【摘要】：利用SERF原子自旋效应能够实现高灵敏度的磁场测量,碱金属原子密度与缓冲气体压强是敏感表头碱金属气室的重要参数,需要精确地测量。提出一种应用原子吸收光谱对碱金属蒸气的原子密度与压强测量方法,通过扫描碱金属原子的吸收光谱,进行Lorentz线型拟合,经解算同时得到原子密度和压强,一次实验获得两个物理量。由于多普勒展宽和压力展宽主要受到碱金属气室温度和缓冲气体压强的影响,从这两个方面进行了仿真分析。结果表明,充入2amg缓冲气体时,313~513K温度范围内的Lorentz线型与Voigt线型计算的光子吸收截面积峰值的理论误差始终小于0.015%;缓冲气体压强高于0.6amg(393K)时,其峰值误差小于0.1%,表明该条件下多普勒展宽对吸收光谱的影响可以忽略,可用Lorentz线型拟合原子的吸收谱线。最后分析了该方法能够获得的理论分辨率以及激光器的功率波动、波长波动和气室温度波动对测量精度的影响,得出同等条件下温度波动的影响比其他两个因素高1~2个数量级。
[Abstract]:The magnetic field measurement with high sensitivity can be realized by using SERF atom spin effect. The density of alkali metal atom and the pressure of buffer gas are important parameters of the sensitive head alkali metal chamber, which need to be accurately measured. A method for measuring atomic density and pressure of alkali metal vapor by atomic absorption spectrometry is proposed. Lorentz line fitting is carried out by scanning the absorption spectrum of alkali metal atom. The atomic density and pressure are obtained simultaneously by calculation. Two physical quantities were obtained in one experiment. Because the Doppler broadening and pressure broadening are mainly affected by the temperature of alkali metal chamber and the pressure of buffer gas, the simulation analysis is carried out from these two aspects. The results show that the theoretical error of peak photon absorption cross-sectional area calculated in the temperature range of 313C 513K and Voigt line is always less than 0.015 when the buffer gas is filled with 2amg buffer gas, and when the buffer gas pressure is higher than 0.6amg / 393K, the theoretical error of peak photon absorption cross-sectional area is always less than 0.015 when the buffer gas pressure is higher than 0.6amg ~ (393K). The peak error is less than 0.1, which indicates that the influence of Doppler broadening on absorption spectra can be neglected, and Lorentz line can be used to fit the absorption lines of atoms. Finally, the influence of theoretical resolution, laser power fluctuation, wavelength fluctuation and temperature fluctuation of gas chamber on the measurement accuracy is analyzed. It is concluded that the influence of temperature fluctuation under the same conditions is 1 ~ 2 orders of magnitude higher than that of the other two factors.
【作者单位】：北京航空航天大学"惯性技术"重点实验室 "新型惯性仪表与导航系统技术"国防重点学科实验室;上海航天控制工程研究所;
【基金】：国家自然基金委重大仪器专项(61227902) 国家自然科学基金项目(61374210) SAST基金项目资助
【分类号】：TG115.33

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