Influence of tungsten fiber’s slow drift on the measurement of G with angular acceleration method
Abstract
In the measurement of the gravitational constant G with angular acceleration method, the equilibrium position of torsion pendulum with tungsten fiber undergoes a linear slow drift, which results in a quadratic slow drift on the angular velocity of the torsion balance turntable under feedback control unit. The accurate amplitude determination of the useful angular acceleration signal with known frequency is biased by the linear slow drift and the coupling effect of the drifting equilibrium position and the room fixed gravitational background signal. We calculate the influences of the linear slow drift and the complex coupling effect on the value of G, respectively. The result shows that the bias of the linear slow drift on G is 7 ppm, and the influence of the coupling effect is less than 1 ppm.
 Authors:
 School of Mechanical Engineering and Electronic Information, China University of Geosciences, Wuhan 430074 (China)
 MOE Key Laboratory of Fundamental Physical Quantities Measurement, School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)
 (China)
 Sternberg Astronomical Institute, Lomonosov Moscow State University, Moscow 119992 (Russian Federation)
 Publication Date:
 OSTI Identifier:
 22597715
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Review of Scientific Instruments; Journal Volume: 87; Journal Issue: 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ACCELERATION; AMPLITUDES; ANGULAR VELOCITY; BALANCES; CONTROL; COUPLING; EQUILIBRIUM; FEEDBACK; FIBERS; MECHANICAL VIBRATIONS; SIGNALS; TIME MEASUREMENT; TORSION; TUNGSTEN
Citation Formats
Luo, Jie, Wu, WeiHuang, Zhan, WenZe, Xue, Chao, School of Physics and Astronomy, Sun Yatsen University, Guangzhou 510275, Shao, ChengGang, Email: cgshao@mail.hust.edu.cn, Wu, JunFei, and Milyukov, Vadim. Influence of tungsten fiber’s slow drift on the measurement of G with angular acceleration method. United States: N. p., 2016.
Web. doi:10.1063/1.4960398.
Luo, Jie, Wu, WeiHuang, Zhan, WenZe, Xue, Chao, School of Physics and Astronomy, Sun Yatsen University, Guangzhou 510275, Shao, ChengGang, Email: cgshao@mail.hust.edu.cn, Wu, JunFei, & Milyukov, Vadim. Influence of tungsten fiber’s slow drift on the measurement of G with angular acceleration method. United States. doi:10.1063/1.4960398.
Luo, Jie, Wu, WeiHuang, Zhan, WenZe, Xue, Chao, School of Physics and Astronomy, Sun Yatsen University, Guangzhou 510275, Shao, ChengGang, Email: cgshao@mail.hust.edu.cn, Wu, JunFei, and Milyukov, Vadim. 2016.
"Influence of tungsten fiber’s slow drift on the measurement of G with angular acceleration method". United States.
doi:10.1063/1.4960398.
@article{osti_22597715,
title = {Influence of tungsten fiber’s slow drift on the measurement of G with angular acceleration method},
author = {Luo, Jie and Wu, WeiHuang and Zhan, WenZe and Xue, Chao and School of Physics and Astronomy, Sun Yatsen University, Guangzhou 510275 and Shao, ChengGang, Email: cgshao@mail.hust.edu.cn and Wu, JunFei and Milyukov, Vadim},
abstractNote = {In the measurement of the gravitational constant G with angular acceleration method, the equilibrium position of torsion pendulum with tungsten fiber undergoes a linear slow drift, which results in a quadratic slow drift on the angular velocity of the torsion balance turntable under feedback control unit. The accurate amplitude determination of the useful angular acceleration signal with known frequency is biased by the linear slow drift and the coupling effect of the drifting equilibrium position and the room fixed gravitational background signal. We calculate the influences of the linear slow drift and the complex coupling effect on the value of G, respectively. The result shows that the bias of the linear slow drift on G is 7 ppm, and the influence of the coupling effect is less than 1 ppm.},
doi = {10.1063/1.4960398},
journal = {Review of Scientific Instruments},
number = 8,
volume = 87,
place = {United States},
year = 2016,
month = 8
}

The performance of the feedback control system is of central importance in the measurement of the Newton's gravitational constant G with angular acceleration method. In this paper, a PID (ProportionIntegrationDifferentiation) feedback loop is discussed in detail. Experimental results show that, with the feedback control activated, the twist angle of the torsion balance is limited to 7.3×10{sup −7} rad /√( Hz ) at the signal frequency of 2 mHz, which contributes a 0.4 ppm uncertainty to the G value.

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