Absolute measurement of thermal noise in a resonant short-range force experiment

作者：Yan H; Housworth E A; Meyer H O; Visser G; Weisman E; Long J C^*

来源：Classical and Quantum Gravity, 2014, 31(20): 205007.

DOI：10.1088/0264-9381/31/20/205007

• short-range tests of gravity
• equipartition theorem
• thermal noise measurements
• torsional oscillators

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, E-exp = (2.0 +/- 0.3) x 10(-21) J, is in agreement with the expected value of 1/2k(B) T.

• 出版日期2014-10-21