An atomic gravitational wave interferometric sensor in low earth orbit (AGIS-LEO)

Abstract

We propose an atom interferometer gravitational wave detector in low Earth orbit (AGIS-LEO). Gravitational waves can be observed by comparing a pair of atom interferometers separated by a 30 km baseline. In the proposed configuration, one or three of these interferometer pairs are simultaneously operated through the use of two or three satellites in formation flight. The three satellite configuration allows for the increased suppression of multiple noise sources and for the detection of stochastic gravitational wave signals. The mission will offer a strain sensitivity of < 10 −18 / √ Hz in the 50 mHz-10 Hz frequency range, providing access to a rich scientific region with 123 1954 J. M. Hogan et al. substantial discovery potential. This band is not currently addressed with the LIGO, VIRGO, or LISA instruments. We analyze systematic backgrounds that are relevant to the mission and discuss how they can be mitigated at the required levels. Some of these effects do not appear to have been considered previously in the context of atom interferometry, and we therefore expect that our analysis will be broadly relevant to atom interferometric precision measurements. Finally, we present a brief conceptual overview of shorter-baseline ( 100 m) atom interferometer configurations that could be deployed as proof-of-principle instruments on the International Space Station (AGIS-ISS) or an independent satellite.

Low-frequency terrestrial gravitational-wave detectors

“…As for the beam jitter case, noise from small-scale aberrations is strongly suppressed [22], and we can focus on the largest scale aberration for the noise estimate, which corresponds to a spatial wavelength equal to half of the beam diameter. In this case, assuming a mirror at room temperature with a coating quality factor Q = 10 4 , the atom phase noise at 0.1 Hz in units of GW strain is less than 10 −24 / √ Hz.…”

Principles of Gravitational Waves Detection Through Atom Interferometry

“…Furthermore, a detailed study of the noise budget for a realistic detector is mandatory to have a reliable comparison between optical and atom interferometers. Florence-Urbino group, among others [35][36][37], is developing a facility as a preliminary fundamental step to test the feasibility of this new GW detector.…”

Newtonian noise limit in atom interferometers for gravitational wave detection

“…This term, already introduced in a different context [34], is a sort of "clock" term which takes into account the influence of the GW on the laser beam, along its path from the source to a well defined physical point. Its role was discussed in recent papers [35][36][37] and the most relevant new property is the introduction of q 1 (path of laser beam) in place of L (path of atom beam); so, in order to improve the sensitivity, enlarging q 1 seems in principle easier than enlarging L.…”