LISA LARGE SCIENTIFIC PROJECT
LISA – A GIANT LASER INTERFEROMETER IN SPACE FOR GRAVITATIONAL WAVES DETECTION
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Nicoleta DINU-JAEGER *, Michel LINTZ Université Côte d’ Azur, Observatoire de la Côte d’ Azur, CNRS, Laboratoire ARTEMIS, 06304 Nice, France * nicoleta. dinu-jaeger @ oca. eu
https:// doi. org / 10.1051 / photon / 202613763
This is an Open Access article distributed under the terms of the Creative Commons Attribution License( https:// creativecommons. org / licenses / by / 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
LISA will be a space-based gravitational-waves observatory to be launched mid-2030, targeting the mHz band, inaccessible from Earth. Using a 2.5 millionkm laser interferometer, it measures pm-scale distance variations between free-falling test masses. This article introduces LISA’ s most critical technologies such as ultra-stable lasers, precision interferometry, ultra-stable optical benches, telescopes, gravitational reference sensors, drag-free control with micro thrusters, Time Delay Interferometry, and stringent stray light control.
Introduction to LISA mission
Gravitational waves( GWs) are perturbations of space-time generated by the accelerated motion of massive systems, such as compact binaries. Propagating at the speed of light, they slightly stretch and compress distances between free-falling objects in orthogonal directions. These effects are extremely small: for astrophysical sources detected so far, relative distance variations are typically ~ 10 – 21.
Predicted by Einstein in 1916 – 1918 [ 1 ], GWs remained undetected for a century. Their observation became possible thanks to modern technologies used by ground-based detectors( LVK Collaboration): narrow-linewidth lasers stabilized to ultra-stable optical cavities, largearea mirrors with extremely low losses, free falling test masses and low-noise photoreceivers. Since 2015, these instruments have detected more than four hundred GWs sources, opening a new era of astronomy [ 2 ].
While ground-based detectors can only observe sources in the audio-frequency band above 20 Hz, low-frequency sources from µ Hz up to 1 Hz can be detected only from space, where the quieter environment avoids terrestrial disturbances such as seismic noise. The concept of a laser-interferometric GWs detector in space emerged in the early 1980s [ 3 ], with the goal of detecting astrophysical objects inaccessible from ground- such as galactic binaries of white dwarfs, mergers of supermassive black holes,
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