Planar, double-torsional oscillators are especially suitable for short-range macroscopic force search experiments, since they can be operated at the limit of instrumental thermal noise. As a study of this limit, we report a measurement of the noise kinetic energy of a polycrystalline tungsten oscillator in thermal equilibrium at room temperature. The fluctuations of the oscillator in a high-Q torsional mode with a resonance frequency near 1 kHz are detected with capacitive transducers coupled to a sensitive differential amplifier. The electronic processing is calibrated by means of a known electrostatic force and input from a finite element model. The measured average kinetic energy is in agreement with the expected value of 1/2 kT.
@article{arxiv.1402.0145,
title = {Absolute measurement of thermal noise in a resonant short-range force experiment},
author = {H. Yan and E. A. Housworth and H. O. Meyer and G. Visser and E. Weisman and J. C. Long},
journal= {arXiv preprint arXiv:1402.0145},
year = {2014}
}
Comments
28 pages, 10 figures, new title, additional references and discussion of force sensitivity, minor corrections