A method with scanning electron microscopy (SEM) is presented to measure the density inhomogeneity of the stainless steel (SS316) sphere prepared for measuring G using time-of-swing method. The experimental result shows that the relative density inhomogeneity of the sphere is better than 5.9×10-4 over the volume of 0.272×0.234×0.005mm3. If we assume that the density inhomogeneity of the spheres used in our G measurement is the same as that of the sphere destroyed in testing, it will contribute to G value with an uncertainty of less than 0.034ppm in our G measurement. Furthermore, the mass centre offset from the geometric centre of the sphere will be less than 4.3×10-4,μm due to this inhomogeneity.
A method with scanning electron microscopy (SEM) is presented to measure the density inhomogeneity of the stainless steel (SS316) sphere prepared for measuring G using time-of-swing method. The experimental result shows that the relative density inhomogeneity of the sphere is better than 5.9×10-4 over the volume of 0.272×0.234×0.005mm3. If we assume that the density inhomogeneity of the spheres used in our G measurement is the same as that of the sphere destroyed in testing, it will contribute to G value with an uncertainty of less than 0.034ppm in our G measurement. Furthermore, the mass centre offset from the geometric centre of the sphere will be less than 4.3×10-4,μm due to this inhomogeneity.
LIU Lin-Xia;SHAO Cheng-Gang;TU Liang-Cheng;LUO Jun. Measurement of Density Inhomogeneity for Source Masses in Time-of-Swing Method of Measuring[J]. 中国物理快报, 2009, 26(1): 10403-010403.
LIU Lin-Xia, SHAO Cheng-Gang, TU Liang-Cheng, LUO Jun. Measurement of Density Inhomogeneity for Source Masses in Time-of-Swing Method of Measuring. Chin. Phys. Lett., 2009, 26(1): 10403-010403.
[1]Cavendish H 1798 Philos. Trans. Roy. Soc. 88469 [2] Luther G G and Towler W R 1982 Phys. Rev. Lett. 48 121 [3] Gundlach J H et al 1996 Phys. Rev. D 54 R1256 [4] Luo J et al 1999 Phys. Rev. D 59 042001 [5] Newman R D et al 1999 Meas. Sci. Technol. 10445 [6] Quinn T J et al 2001 Phys. Rev. Lett. 87111101 [7] Fixler J B et al 2007 Science 315 74 [8] Hu Z K et al 2001 Chin. Phys. Lett. 18 7 [9] Luo J et al 2000 Rev. Sci. Instrum. 71 1524 [10] Gundlach J H et al 1997 Phys. Rev. Lett. 782523 [11] Gillies G T et al 1993 Rev. Sci. Instrum. 64283 [12] Guo J Q et al 2004 Chin. Phys. Lett. 21 612 [13] Hu Z K et al 2005 Phys. Rev. D. 71 127505-1 [14] Peter J M and Barry N T 2000 Rev. Mod. Phys. 72 351 [15] Liu L X et al 2008 Chin. Phys. Lett. 25 4203 [16] Shiomi S et al 2001 Class. Quantum Grav. 182533 [17] Fitzgerald M P et al 1994 Metrologia 31 301 [18] Conklin J W et al 2006 AIP Conf. Proc. 873566 [19] Lamporesi G et al 2007 Rev. Sci. Instrum. 78075109 [20] Lloyd G E 1987 Mineral. Mag. 51 3 [21] Scrivener K L 2004 Cem. Concr. Compos. 26 935
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