【摘要】 氩气等单原子气体的折射率,是检验量子力学从头算理论的重要参数。基于圆柱微波谐振法,精确测量了234～303 K、0～750 k Pa范围内氩气的折射率。测量了圆柱腔内不同压力下4种横磁(TM)模式的微波谐振频率,对谐振频率进行非理想因素修正后,结合真空下的微波谐振频率获得氩气的折射率。圆柱腔内微波谐振频率测量不确定度为2×10-8,4种模式获得的氩气折射率的相对标准偏差小于1×10-6。通过氩气的折射率计算获得了氩气的第一介电维里系数,与国际上已发表的结果具有良好的一致性。基于建立的实验系统,后续可开展其他气体的折射率测量。更多还原

【Abstract】 The refractive index of monatomic gases such as argon is an important parameter for the verification of the ab initio calculations based on quantum mechanics. The refractive index of argon from 234 K to 303 K and 0 k Pa to 750 k Pa was measured accurately using a cylindrical microwave resonator. Microwave resonance frequencies of four TM modes at different pressures in a cylindrical cavity were measured. After the correction of the non-ideal factors,the refractive index of argon was obtained by the comparison of the microwave resonance frequencies in vacuum and in gases. The uncertainty of microwave resonance frequency in the cylindrical cavity is 2 × 10-8,and the inconsistence between the argon refractive index from four modes is less than 1 × 10-6. The first dielectric virial coefficients of argon are obtained by calculating the refractive index of argon,and the results show a good agreement with the published results. The refractive index measurement of other gases can be carried out in the future using the experimental apparatus.更多还原