Effects of temperature fluctuations on a SQUID-based superconducting gravimeter

A superconducting gravimeter based on the superconducting quantum interference device system is under development. As the main source of low-frequency noise, temperature fluctuations affect the resolution of superconducting gravimeters. In this study, a set of experimental devices was built to investigate the primary coupling processes of temperature fluctuations in superconducting gravimeters. Under the temperature modulation method, the effects of temperature fluctuations can be expressed as d Phi/dT = 342(2)Phi(0)/K, which, according to theoretical analysis, corresponds to a displacement change of (1.38 +/- 0.04) x 10(-7) m/K. Based on these results, the ambient temperature is controlled to within +/- 100 mu K, and the equivalent effect of temperature fluctuations on our superconducting gravimeter is 0.5 mu Gal.