The investigation of a μGal-level cold atom gravimeter for field applications

Abstract

Typical atomic gravimeters have a heavy magnetic shielding to avoid the quadratic Zeeman effect, and also a complicated active vibration isolation system to suppress the vibration noise. Both of them make it difficult to build a mobile and compact gravimeter. In this paper, we present the implementation of an atomic gravimeter aiming at field applications. Our gravimeter uses improved magnetic coils instead of the expensive mu-metal for magnetic shielding. The quadratic Zeeman shift is evaluated with high accuracy. Moreover, a portable platform of relatively small size is applied for vibration isolation. The total interrogation time is optimized to 120 ms and the repetition rate is 2.2 Hz. A sensitivity of 1.0 × 10−7 g Hz−1/2 and a resolution of 5.7 × 10−9 g within 1000 s integration time are reached. A continuous g measurement over 128 h is carried out. Moreover, a whole seismic wave of about 1 h that occurred in Pakistan on 28 September 2013 is recorded by our atomic gravimeter. The results coincide with that recorded by a traditional seismic detector very well.

A portable magneto-optical trap with prospects for atom interferometry in civil engineering

“…The exceptional promise of laboratory systems and their inherent low drift has led to a global push towards making transportable atom interferometry systems [11][12][13][14], targeting a range of future applications. This has focused on reductions in the size of the components needed (such as in the European project, iSense) and in the adoption of more robust technology, culminating in a range of systems being developed for outside of the typical laboratory setting.…”

Monitoring of a geothermal reservoir by hybrid gravimetry; feasibility study applied to the Soultz-sous-Forêts and Rittershoffen sites in the Rhine graben

“…Moreover, new instruments are available, like the portable superconducting gravimeter iGrav (Warburton et al 2010) or will be available soon, like the cold atom absolute gravimeter (Bidel et al 2013;Wu et al 2014;Merlet et al 2010) that will even improve in the near future this potentiality.…”

Multiport atom interferometry for inertial sensing

“…With these techniques, we realize two types of multiport measurements, namely quadrature phase detection and real-time systematic phase cancellation, which address challenges in operating high-sensitivity cold-atom sensors in mobile and field applications. We confirm experimentally the increase in sensitivity due to quadrature phase detection in the presence of large phase uncertainty, and demonstrate suppression of systematic phases on a single shot basis.Cold atom interferometers have demonstrated extremely high sensitivity as inertial sensors measuring gravity [1][2][3], gravity gradients [4][5][6][7][8], accelerations and rotations [9][10][11][12][13][14][15][16][17]. In addition to precision measurements of physical constants [18][19][20][21][22], tests of general relativity [23][24][25][26][27][28], searches for dark energy [29,30], and gravitational wave detection [31,32], they are promising candidates as on-board inertial measurement units [10,[33][34][35] and as mobile gravimeters for geodesic studies or subterranean exploration [36][37][38][39][40][41]…”

“…Both multiport schemes are compatible with many Raman atom interferometers, including different pulse sequences such as π/2-π-π-π/2 for rotation sensing [10][11][12][13] and large momentum transfer interferometers [47,48]. Interferometers operating in micro-gravity [33], where atoms are scattered into multiple momentum states due to vanishing Doppler shift [?…”