Evaluating residual acceleration noise for the TianQin gravitational waves observatory with an empirical magnetic field model
Evaluating residual acceleration noise for the TianQin gravitational waves observatory with an empirical magnetic field model
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DOI：
10.1103/physrevd.108.103030
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发表时间：
2023-10
影响因子：
5
通讯作者：
Wei Su;Zebing Zhou;Yan Wang;Chen Zhou;P. F. Chen;Wei Hong;J. Peng;Yun Yang;Y. Ni
中科院分区：
文献类型：
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作者：
Wei Su;Zebing Zhou;Yan Wang;Chen Zhou;P. F. Chen;Wei Hong;J. Peng;Yun Yang;Y. Ni
天琴工程计划在地球周围的空间部署三颗卫星，通过激光干涉测量技术测量引力波引起的试验质量的位移变化。在TQ的敏感频率范围内，对试验质量的加速度噪声的要求为10 ^{-15}~\，{\rm m}\，{\rm s}^{-2}\，{\rm Hz}^{-1/2}$，极精确的加速度测量要求使得有必要研究由于空间磁场引起的加速度噪声。这是如此严格，以至于需要研究由空间磁场与测试质量的相互作用引起的加速噪声。本文利用Tsyganenko空间磁场经验模型，计算了1998 - 2020年23年间TQ轨道上的磁场分布。利用得到的空间磁场，计算了23年来TQ加速度噪声的分布和幅值谱密度。结果表明，在1 mHz（R_{\rm 1 mHz}$）和6 mHz（R_{\rm 6 mHz}$）时，空间磁场引起的加速度噪声与TQ要求的比值平均值分别为0.123$\pm$0.052和0.027$\pm$0.013。$R_{\rm 1 mHz}$>0.2$和$>0.3$的出现概率分别仅为7.9%和1.2%，$R_{\rm 6 mHz}$从未超过0.2。
TianQin (TQ) project plans to deploy three satellites in space around the Earth to measure the displacement change of test masses caused by gravitational waves via laser interferometry. The requirement of the acceleration noise of the test mass is on the order of $10^{-15}~\,{\rm m}\,{\rm s}^{-2}\,{\rm Hz}^{-1/2}$ in the sensitive frequency range of TQ, %the extremely precise acceleration measurement requirements make it necessary to investigate acceleration noise due to space magnetic fields. which is so stringent that the acceleration noise caused by the interaction of the space magnetic field with the test mass needs to be investigated. In this work, by using the Tsyganenko model, a data-based empirical space magnetic field model, we obtain the magnetic field distribution around TQ's orbit spanning two solar cycles in 23 years from 1998 to 2020. With the obtained space magnetic field, we derive the distribution and amplitude spectral densities (ASDs) of the acceleration noise of TQ in 23 years. Our results reveal that the average values of the ratio of the acceleration noise cauesd by the space magnetic field to the requirements of TQ at 1 mHz ($R_{\rm 1mHz}$) and 6 mHz ($R_{\rm 6mHz}$) are 0.123$\pm$0.052 and 0.027$\pm$0.013, respectively. The occurence probabilities of $R_{\rm 1mHz}>0.2$ and $>0.3$ are only 7.9% and 1.2%, respectively, and $R_{\rm 6mHz}$ never exceeds 0.2.