In: Physics of the Dark Universe, 2020, vol. 28, p. 100494
The Global Network of Optical Magnetometers for Exotic physics searches (GNOME) is a network of time-synchronized, geographically separated, optically pumped atomic magnetometers that is being used to search for correlated transient signals heralding exotic physics. GNOME is sensitive to exotic couplings of atomic spins to certain classes of dark matter candidates, such as axions. This work...
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In: IEEE Transactions on Medical Imaging, 2020, vol. 39, no. 4, p. 922–933
We introduce a Magnetic Particle Imaging Susceptometer (MPIS) that uses a high- sensitivity atomic magnetometer (AM) for recording the spatial distribution of fluid- suspended magnetic nanoparticles. We have evaluated the MPIS performance by one-dimensional scans of structured nanoparticle phantoms, demonstrating, in particular, resolutions of ≈2.5 mm prior to deconvolution and ≪1 mm after ...
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In: Journal of Low Temperature Physics, 2011, vol. 165, no. 3-4, p. 166-176
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In: Applied Physics B, 2014, vol. 115, no. 1, p. 85–91
We propose a precision method for the in situ calibration of a three-axis coil system based on the free-induction decay of spin-aligned atoms. In addition, we present a simple and efficient method for measuring the three-vector components of a residual magnetic field.
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In: Journal of Low Temperature Physics, 2011, vol. 165, no. 3-4, p. 166-176
Laser ablation of metals in liquid helium results in the formation of metal filaments with diameters on the order of 2–10 nanometres and of spherical nanoparticles. In superfluid helium these nanowires aggregate into centimeter-sized networks. We study the morphology and the electric conductivity of these large aggregates, as well as extinction spectra and the crystalline structure of the...
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In: Applied Physics B, 2009, vol. 96, no. 4, p. 763-772
We have manufactured more than 250 nominally identical paraffin-coated Cs vapor cells (28 mm inner diameter bulbs) for multi-channel atomic magnetometer applications. We describe our dedicated cell characterization apparatus. For each cell we have determined the intrinsic longitudinal, Γ ₀₁, and transverse, Γ ₀₂, relaxation rates. Our best cell shows Γ...
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In: Fizika Nizkikh Temperatur, 2006, vol. 32, no. 11, p. 1297-1319
A little more than a decade ago our team extended the field of defect spectroscopy in cryocrystals to solid ⁴He matrices, in both their body-centered cubic (bcc) and hexagonally close-packed (hcp) configurations. In this review paper we survey our pioneering activities in the field and compare our results to those obtained in the related fields of doped superfluid helium and doped helium...
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In: Journal of Research of the National Institute of Standards and Technology, 2005, vol. 110, p. 179-183
We designed laser-pumped cesium vapor magnetometers in the Mx configuration for the control and stabilization of magnetic field fluctuations and gradients in a new experiment searching for a permanent electric dipole moment of the neutron. The intrinsic sensitivity of the device was determined to be 30 fT in a measurement bandwidth of 1 Hz, limited by laser noise. In the shot noise...
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In: Applied Physics B: Lasers and Optics, 2005, vol. 80(6), p. 645 - 654
We have performed a comparison of laser (LsOPM) and lamp (LpOPM) pumped cesium vapor magnetometers. Although the LsOPM operated 50% above its shot- noise limit we found an intrinsic sensitivity of 15 fT/√Hz and 25 fT/√Hz for the LsOPM and the LpOPM, respectively. Two modes of operation, viz. the phase-stabilized and the self-oscillating modes, were investigated and found to yield a similar...
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In: Journal of the Optical Society of America: B, 2005, vol. 22 No. 1, p. 77-87
Cardiomagnetometry is a growing field of noninvasive medical diagnostics that has triggered a need for affordable high-sensitivity magnetometers. Optical pumping magnetometers (OPMs) are promising candidates for satisfying that need since it has been demonstrated that they can be used to map the magnetic field of the beating human heart. We discuss the principle of a phase-detecting OPM and...
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