Approaching Free Fall on Two Degrees of Freedom: Simultaneous Measurement of Residual Force and Torque on a Double Torsion Pendulum

作者：Bassan M^*; Cavalleri A; De Laurentis M; De Marchi F; De Rosa R; Di Fiore L^*; Dolesi R; Finetti N; Garufi F; Grado A; Hueller M; Marconi L; Milano L; Pucacco G; Stanga R; Visco M; Vitale S; Weber W J

来源：Physical Review Letters, 2016, 116(5): 051104.

DOI：10.1103/PhysRevLett.116.051104

A torsion pendulum with 2 soft degrees of freedom (DOFs), realized by off-axis cascading two torsion fibers, has been built and operated. This instrument helps characterize the geodesic motion of a test mass for LISA Pathfinder or any other free-fall space mission, providing information on cross talk and other effects that cannot be detected when monitoring a single DOF. We show that it is possible to simultaneously measure both the residual force and the residual torque acting on a quasifree test mass. As an example of the investigations that a double pendulum allows, we report the measurement of the force-to-torque cross talk, i.e., the amount of actuation signal, produced by applying a force on the suspended test mass, that leaks into the rotational DOF, detected by measuring the corresponding (unwanted) torque.

• 出版日期2016-2-5