In: Physical Review A, 2019, vol. 99, no. 4, p. 042112
Magnetic-field uniformity is of the utmost importance in experiments to measure the electric dipole moment of the neutron. A general parametrization of the magnetic field in terms of harmonic polynomial modes is proposed, going beyond the linear- gradients approximation. We review the main undesirable effects of nonuniformities: depolarization of ultracold neutrons and Larmor frequency shifts...
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In: Physical Review X, 2017, vol. 7, no. 4, p. 041034
We report on a search for ultralow-mass axionlike dark matter by analyzing the ratio of the spin-precession frequencies of stored ultracold neutrons and 199Hg atoms for an axion-induced oscillating electric dipole moment of the neutron and an axion-wind spin-precession effect. No signal consistent with dark matter is observed for the axion mass range 10−24≤ma≤10−17 eV. Our null result...
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In: Physical Review D, 2015, vol. 92, no. 9, p. 092003
We present for the first time a detailed and comprehensive analysis of the experimental results that set the current world sensitivity limit on the magnitude of the electric dipole moment (EDM) of the neutron. We have extended and enhanced our earlier analysis to include recent developments in the understanding of the effects of gravity in depolarizing ultracold neutrons; an improved calculation...
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In: Physical Review Letters, 2015, vol. 115, no. 16, p. 162502
We describe a spin-echo method for ultracold neutrons (UCNs) confined in a precession chamber and exposed to a |B0|=1 μT magnetic field. We have demonstrated that the analysis of UCN spin-echo resonance signals in combination with knowledge of the ambient magnetic field provides an excellent method by which to reconstruct the energy spectrum of a confined ensemble of neutrons. The method...
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In: Physics Letters B, 2015, vol. 745, p. 58–63
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In: Journal of Applied Physics, 2014, vol. 116, no. 8, p. 084510
The Surrounding Field Compensation (SFC) system described in this work is installed around the four-layer Mu-metal magnetic shield of the neutron electric dipole moment spectrometer located at the Paul Scherrer Institute. The SFC system reduces the DC component of the external magnetic field by a factor of about 20. Within a control volume of approximately 2.5 m × 2.5 m × 3 m,...
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