Readout system and predicted performance of a low-noise low-frequency horizontal accelerometer

Abstract The readout system of a new very low noise low-frequency, force-feedback accelerometer is presented. The horizontal accelerometer carrying this sensor has been designed to be integrated in an advanced seismic isolation system for interferometric gravitational wave detectors. To make it suitable for ultra-high-vacuum operation and to reduce the probability of failures of the in-vacuum components, the accelerometer is equipped with a high-resolution capacitance sensor fully driven by remote signal conditioning electronics. The instrument's performance is not compromised by cabling lengths of up to 15 m. The accelerometer, equipped with this readout scheme, should be able to detect the inertial displacement of a platform with a root-mean-square noise less than 1 nm, integrated over all the frequencies above 0.01 Hz. We plan to implement the same readout scheme in a companion vertical sensor now being designed.

[1]  Naresh K. Sinha,et al.  Modern Control Systems , 1981, IEEE Transactions on Systems, Man, and Cybernetics.

[2]  Jonathan P. How,et al.  Seismic isolation for Advanced LIGO , 2002 .

[3]  Nicolo' Beverini,et al.  Geometric anti-spring vertical accelerometers for seismic monitoring , 2004 .

[4]  A. Giassi,et al.  Low noise wideband accelerometer using an inductive displacement sensor , 1995 .

[5]  E. Wielandt,et al.  An electronic long-period seismograph for surface-wave dispersion studies , 1976, Bulletin of the Seismological Society of America.

[6]  C. Speake,et al.  Capacitive sensing for drag-free satellites , 1997 .

[7]  Renzo Valentini,et al.  Seismic isolation by mechanical filters at very low frequencies , 1998 .

[8]  Pierre Touboul,et al.  Electrostatic space accelerometers for present and future missions 1 1 Based on paper IAF.96.J1.02 p , 1999 .

[9]  Robert D. Moore,et al.  Measurements in the Earth mode frequency range by an electrostatic sensing and feedback gravimeter , 1966 .

[10]  R. V. Jones,et al.  REVIEW ARTICLE: The design and some applications of sensitive capacitance micrometers , 1973 .

[11]  P. Saulson,et al.  Thermal noise in mechanical experiments. , 1990, Physical review. D, Particles and fields.

[12]  P. Touboul,et al.  Capacitive detection scheme for space accelerometers applications , 1999 .

[13]  F. Klopping,et al.  From Chandler wobble to free oscillations: comparison of cryogenic gravimeters and other instruments in a wide period range , 1995 .

[14]  M J Usher,et al.  A miniature wideband horizontal-component feedback seismometer , 1977 .

[15]  Hiroaki Yamamoto,et al.  Anatomy of the TAMA SAS seismic attenuation system , 2002 .