A TRANSPORTABLE HIGH-PRECISION ABSOLUTE ATOMIC GRAVIMETER

Abstract

Gravimeters based on atom interferometry offer high stability in measuring local gravitational acceleration by referencing the acceleration of free-falling atomic test masses with the frequency standard. A Raman light-pulse atomic gravimeter based on ultracold Rubidium-87 with a single seed laser has been designed and realized on a transportable platform of dimensions 180 X 80 X 80 cm. The gravimeter is capable of running the measurements from a remote location. A compact vibration stabilization system based on active feedback cancellation has also been realized on the retro-reflecting mirror of the Raman lasers, achieving vibration noise at the level of 10^(-9) g/sqrt(Hz) in the frequency range of 0.1 Hz to 10 Hz. The tilt angles of the retro-reflecting mirror in the two axes have also been stabilized to within 0.1 millidegree. We achieved resolution of about 9.4 µGal with 2.5 minutes of integration time in measuring local gravitational acceleration.