Université de Fribourg

Magnetic-field uniformity in neutron electric-dipole-moment experiments

Abel, C. ; Ayres, N. J. ; Baker, T. ; Ban, G. ; Bison, G. ; Bodek, K. ; Bondar, V. ; Crawford, C. B. ; Chiu, P.-J. ; Chanel, E. ; Chowdhuri, Z. ; Daum, M. ; Dechenaux, B. ; Emmenegger, S. ; Ferraris-Bouchez, L. ; Flaux, P. ; Geltenbort, P. ; Green, K. ; Griffith, W. C. ; Grinten, M. van der ; Harris, P. G. ; Henneck, R. ; Hild, N. ; Iaydjiev, P. ; Ivanov, S. N. ; Kasprzak, M. ; Kermaidic, Y. ; Kirch, K. ; Koch, H.-C. ; Komposch, S. ; Koss, P. A. ; Kozela, A. ; Krempel, J. ; Lauss, B. ; Lefort, T. ; Lemiere, Y. ; Leredde, A. ; Mohanmurthy, P. ; Pais, D. ; Piegsa, F. M. ; Pignol, G. ; Quéméner, G. ; Rawlik, M. ; Rebreyend, D. ; Ries, D. ; Roccia, S. ; Rozpedzik, D. ; Schmidt-Wellenburg, P. ; Schnabel, A. ; Severijns, N. ; Virot, R. ; Weis, Antoine ; Wursten, E. ; Wyszynski, G. ; Zejma, J. ; Zsigmond, G.

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...

Université de Fribourg

Search for axionlike dark matter through nuclear spin precession in electric and magnetic fields

Abel, C. ; Ayres, N.?J. ; Ban, G. ; Bison, G. ; Bodek, K. ; Bondar, V. ; Daum, M. ; Fairbairn, M. ; Flambaum, V.?V. ; Geltenbort, P. ; Green, K. ; Griffith, W.?C. ; Grinten, M. van der ; Grujiæ, Z.?D. ; Harris, P.?G. ; Hild, N. ; Iaydjiev, P. ; Ivanov, S.?N. ; Kasprzak, M. ; Kermaidic, Y. ; Kirch, K. ; Koch, H.-C. ; Komposch, S. ; Koss, P.?A. ; Kozela, A. ; Krempel, J. ; Lauss, B. ; Lefort, T. ; Lemi?re, Y. ; Marsh, D.?J.?E. ; Mohanmurthy, P. ; Mtchedlishvili, A. ; Musgrave, M. ; Piegsa, F.?M. ; Pignol, G. ; Rawlik, M. ; Rebreyend, D. ; Ries, D. ; Roccia, S. ; Rozpêdzik, D. ; Schmidt-Wellenburg, P. ; Severijns, N. ; Shiers, D. ; Stadnik, Y.?V. ; Weis, Antoine ; Wursten, E. ; Zejma, J. ; Zsigmond, G.

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...

Université de Fribourg

Losses and depolarization of ultracold neutrons on neutron guide and storage materials

Bondar, V. ; Chesnevskaya, S. ; Daum, M. ; Franke, B. ; Geltenbort, P. ; Göltl, L. ; Gutsmiedl, E. ; Karch, J. ; Kasprzak, Malgorzata ; Kessler, G. ; Kirch, K. ; Koch, Hans-Christian ; Kraft, Andreas ; Lauer, Thorsten ; Lauss, B. ; Pierre, E. ; Pignol, G. ; Reggiani, D. ; Schmidt-Wellenburg, P. ; Sobolev, Yuri ; Zechlau, T. ; Zsigmond, G.

In: Physical Review C, 2017, vol. 96, no. 3, p. 035205

At Institut Laue-Langevin (ILL) and Paul Scherrer Institute (PSI), we have measured the losses and depolarization probabilities of ultracold neutrons on various materials: (i) nickel-molybdenum alloys with weight percentages of 82/18, 85/15, 88/12, 91/9, and 94/6 and natural nickel Ni100, (ii) nickel-vanadium NiV93/7, (iii) copper, and (iv) deuterated polystyrene (dPS). For the different...

Université de Fribourg

A device for simultaneous spin analysis of ultracold neutrons

Afach, S. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Chowdhuri, Z. ; Daum, M. ; Fertl, M. ; Franke, B. ; Geltenbort, P. ; Grujić, Zoran. D. ; Hayen, L. ; Hélaine, V. ; Henneck, R. ; Kasprzak, Malgorzata ; Kermaïdic, Y. ; Kirch, K. ; Komposch, S. ; Kozela, A. ; Krempel, J. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; Mtchedlishvili, A. ; Cuncic, O. Naviliat ; Piegsa, F. M. ; Pignol, G. ; Prashanth, P. N. ; Quéméner, G. ; Rawlik, M. ; Ries, D. ; Rebreyend, D. ; Roccia, S. ; Rozpedzik, D. ; Wellenburg, P. Schmidt ; Severijns, N. ; Weis, Antoine ; Wursten, E. ; Wyszynski, G. ; Zejma, J. ; Zsigmond, G.

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...

Université de Fribourg

Observation of gravitationally induced vertical striation of polarized ultracold neutrons by spin-echo spectroscopy

Afach, S. ; Ayres, N. J. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Chowdhuri, Z. ; Daum, M. ; Fertl, M. ; Franke, B. ; Griffith, W. C. ; Grujić, Z. D. ; Harris, P. G. ; Heil, W. ; Hélaine, V. ; Kasprzak, Malgorzata ; Kermaidic, Y. ; Kirch, K. ; Knowles, Paul E. ; Koch, H.-C. ; Komposch, S. ; Kozela, A. ; Krempel, J. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; Mtchedlishvili, A. ; Musgrave, M. ; Naviliat-Cuncic, O. ; Pendlebury, J. M. ; Piegsa, F. M. ; Pignol, G. ; Plonka-Spehr, C. ; Prashanth, P. N. ; Quéméner, G. ; Rawlik, M. ; Rebreyend, D. ; Ries, D. ; Roccia, S. ; Rozpedzik, D. ; Schmidt-Wellenburg, P. ; Severijns, N. ; Thorne, J. A. ; Weis, Antoine ; Wursten, E. ; Wyszynski, G. ; Zejma, J. ; Zenner, J. ; Zsigmond, G.

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...

Université de Fribourg

A measurement of the neutron to 199Hg magnetic moment ratio

Afach, S. ; Baker, C. A. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Burghoff, M. ; Chowdhuri, Z. ; Daum, M. ; Fertl, M. ; Franke, B. ; Geltenbort, P. ; Green, K. ; Grinten, M. G. D. van der ; Grujic, Zoran ; Harris, P. G. ; Heil, W. ; Hélaine, V. ; Henneck, R. ; Horras, M. ; Iaydjiev, P. ; Ivanov, S. N. ; Kasprzak, Malgorzata ; Kermaïdic, Y. ; Kirch, K. ; Knecht, A. ; Koch, Hans-Christian ; Krempel, J. ; Kuźniak, M. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Pendlebury, J. M. ; Perkowski, M. ; Pierre, E. ; Piegsa, F. M. ; Pignol, G. ; Prashanth, P. N. ; Quéméner, G. ; Rebreyend, D. ; Ries, D. ; Roccia, S. ; Schmidt-Wellenburg, P. ; Schnabel, A. ; Severijns, N. ; Shiers, D. ; Smith, K.F. ; Voigt, J. ; Weis, Antoine

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).

Université de Fribourg

Dynamic stabilization of the magnetic field surrounding the neutron electric dipole moment spectrometer at the Paul Scherrer Institute

Afach, S. ; Bison, Georg ; Bodek, K. ; Burri, F. ; Chowdhuri, Z. ; Daum, M. ; Fertl, M. ; Franke, B. ; Grujic, Z. ; Hélaine, V. ; Henneck, R. ; Kasprzak, Malgorzata ; Kirch, K. ; Koch, H.-C. ; Kozela, A. ; Krempel, J. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; Meier, M. ; Naviliat-Cuncic, O. ; Piegsa, F. M. ; Pignol, G. ; Plonka-Spehr, C. ; Prashanth, P. N. ; Quéméner, G. ; Rebreyend, D. ; Roccia, S. ; Schmidt-Wellenburg, P. ; Schnabel, A. ; Severijns, N. ; Voigt, J. ; Weis, Antoine ; Wyszynski, G. ; Zejma, J. ; Zenner, J. ; Zsigmond, G.

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,...