Acceleration

Physics

Gravitation

Atom interferometer

Gravitational constant

Magnetic field

Optics

Engineering

Gravimeter

Magnetometer

Interferometry

Sensitivity (control systems)

Astronomical interferometer

Electronic engineering

Gradiometer

Quantum mechanics

Gravitational acceleration

Classical mechanics

Review of Scientific Instruments

As part of a program to determine the gravitational constant G using multiple independent methods in the same laboratory, an atom gravity gradiometer is being developed. The gradiometer is designed with two magneto-optical traps to ensure both the fast simultaneous launch of two atomic clouds and an optimized configuration of source masses. Here, the design of the G measurement by atom interferometry is detailed, and the experimental setup of the atom gravity gradiometer is reported. A preliminary sensitivity of 3 × 10−9 g/Hz to differential gravity acceleration is obtained, which corresponds to 99 E/Hz (1 E = 10−9 s−2) for the gradiometer with a baseline of 0.3 m. This provides access to measuring G at the level of less than 200 parts per million in the first experimental stage.

A dual-magneto-optical-trap atom gravity gradiometer for determining the Newtonian gravitational constant