Funded by the ANR, MIGA is an “Equipement d’Excellence” project which aims at building the first laser-based atomic interferometer to study variations of the strain tensor of space-time and gravitation. Using a novel approach based on quantum mechanics, this equipment will enable us to deepen our understanding of the terrestrial gravitational field on a wide frequency window ranging from a few tenth of Hertz to several hundreds.
million € EQUIPEX funding over 7 years
partners within the consortium
meter-long instrument under construction in Rustrel, France
The MIGA antenna baseline is designed to reach high sensitivity at low frequency. It consists in a chain of three atom interferometers distributed along a single beam path. The laser beam used to drive the matter-wave interferometer laser pulses is also locked to a resonant cavity. Each atom interferometer measures the local accelerations felt by the atoms with respect to the cavity mirrors. A differential measurement between the atom interferometers removes the mirror contribution to the signal and results in gravity gradient, gravity curvature or higher moments readout.
High precision is reached because the atoms are in free fall, and the implementation of atom interferometers with long interrogation time relies on the use of atoms launched along a parabolic trajectory as demonstrated in [Canuel 2006]. Interrogation times of 200 ms will be reached with an “active interrogation area” of diameter 20 cm, thus requiring a beam diameter in the cavity of at least 30 cm (a 10 cm radium would lead to a 4-fold loss in sensitivity).
MIGA will be installed at the LSBB, an underground low-noise laboratory located in
Rustrel, near the city of Apt in Vaucluse, France. The LSBB is a European
interdisciplinary laboratory for science and technology created in 1997 from the
decommissioning of a launching control system of the French strategic nuclear defense
operative during the Cold War. The LSBB is now an underground scientific platform
characterized by an ultra-low noise environment, both seismic and electromagnetic,
as a result of the distance of the site from heavy industrial and human activities. The
LSBB fosters trans-disciplinary interactions and interdisciplinary approaches, pursuing
both fundamental and applied research. The result is a broad scientific and industrial
expertise, besides the openness to European and international research programs
and groups. The LSBB is an ideal facility for site studies of next generation GW
detectors and more generally for the improvement of low-frequency sensitivity of existing
and future GW antennas. In such environment, MIGA aims at studying Newtonian
Noise and testing advanced detector geometries for its cancellation.
The project MIGA has been approved and funded under the French program ``Investissements d'Avenir`` as an excellence Equipment.
2019 is the final stage of MIGA, starting with the building of the undeground galleries.