In: The European Physical Journal D, 2015, vol. 69, no. 11, p. 1–11
We report on extensive studies on the intrinsic sensitivity of a combined ³He/Cs magnetometer. The magnetometer relies on the detection of the free spin precession of nuclear spin polarized ³He by optically pumped cesium magnetometers. We characterize the relevant processes involved in the detection and quantify their impact on the total sensitivity of the magnetometer. An expression is derived...
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In: The European Physical Journal A, 2015, vol. 51, no. 11, p. 1–10
We report on the design and first tests of a device allowing for measurement of ultracold neutrons polarisation by means of the simultaneous analysis of the two spin components. The device was developed in the framework of the neutron electric dipole moment experiment at the Paul Scherrer Institute. Individual parts and the entire newly built system have been characterised with ultracold...
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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: The European Physical Journal D, 2015, vol. 69, no. 8, p. 1–12
We report on the design and performance of a highly sensitive combined ³He/Cs magnetometer for the absolute measurement of magnetic fields. The magnetometer relies on the magnetometric detection of the free spin precession of nuclear spin polarized ³He gas by optically pumped cesium magnetometers. We plan to deploy this type of combined magnetometer in an experiment searching for a permanent...
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In: Physics Letters B, 2015, vol. 745, p. 58–63
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In: Physics Letters B, 2014, vol. 739, p. 128–132
The neutron gyromagnetic ratio has been measured relative to that of the 199Hg atom with an uncertainty of 0.8 ppm. We employed an apparatus where ultracold neutrons and mercury atoms are stored in the same volume and report the result γn/γHg=3.8424574(30)γn/γHg=3.8424574(30).
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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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In: Physics Procedia, 2011, vol. 17, p. 159-167
The measurement of the neutron electric dipole moment (nEDM) constrains the contribution of CP-violating terms within both the Standard Model and its extensions. The experiment uses ultracold neutrons (UCN) stored in vacuum at room temperature. This technique provided the last (and best) limit by the RAL/Sussex/ILL collaboration in 2006: dn < 2:9 × 10⁻²⁶ e cm (90% C.L.). We aim to improve...
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In: EPL - Europhysics Letters, 2011, vol. 95, no. 1, p. 12001
Ultracold neutrons (UCN) have been produced using the cold neutron (CN) beam FUNSPIN at SINQ on cryogenic oxygen (O₂), tetradeuteromethane (C²H₄), and deuterium (²H₂) targets. The target cell (40 mm long, fiducial volume about 45 cm³) was operated between room temperature and 8 K and UCN were produced from gaseous, liquid and solid targets. UCN rates have been measured as a convolution...
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In: Physics Procedia, 2011, vol. 17, p. 259-267
The nEDM experiment hosted at the Paul Scherrer Institute is the flagship project at the new ultracold neutron facility. Estimations of systematic effects for the determination of the neutron electric dipole moment play an important role in this project. Experimental studies are supported by Monte Carlo simulations using the MCUCN code. Here we briefly present first results on the experimental...
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