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

Revised experimental upper limit on the electric dipole moment of the neutron

Pendlebury, J. M. ; Afach, S. ; Ayres, N. J. ; Baker, C. A. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Burghoff, M. ; Geltenbort, P. ; Green, K. ; Griffith, W. C. ; Grinten, M. van der ; Grujić, Z. D. ; Harris, P. G. ; Hélaine, V. ; Iaydjiev, P. ; Ivanov, S. N. ; Kasprzak, M. ; Kermaidic, Y. ; Kirch, K. ; Koch, H.-C. ; Komposch, S. ; Kozela, A. ; Krempel, J. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; May, D. J. R. ; Musgrave, M. ; Naviliat-Cuncic, O. ; Piegsa, F. M. ; Pignol, G. ; Prashanth, P. N. ; Quéméner, G. ; Rawlik, M. ; Rebreyend, D. ; Richardson, J. D. ; Ries, D. ; Roccia, S. ; Rozpedzik, D. ; Schnabel, A. ; Schmidt-Wellenburg, P. ; Severijns, N. ; Shiers, D. ; Thorne, J. A. ; Weis, Antoine ; Winston, O. J. ; Wursten, E. ; Zejma, J. ; Zsigmond, G.

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...

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

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

The search for the neutron electric dipole moment at the Paul Scherrer Institute

Baker, C.A. ; Ban, G. ; Bodek, K. ; Burghoff, M. ; Chowdhuri, Z. ; Daum, M. ; Fertl, M. ; Franke, B. ; Geltenbort, P. ; Green, K. ; Grinten, M.G.D. van der ; Gutsmiedl, E. ; Harris, P.G. ; Henneck, R. ; Iaydjiev, P. ; Ivanov, S.N. ; Khomutov, N. ; Kasprzak, Malgorzata ; Kirch, K. ; Kistryn, S. ; Knappe-Gr̈uneberg, S. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; Naviliat-Cuncic, O. ; Pendlebury, J.M. ; Pierre, E. ; Piegsa, F.M. ; Pignol, G. ; Quéméner, G. ; Roccia, S. ; Schmidt-Wellenburg, P. ; Shiers, D. ; Smith, K.F. ; Schnabel, A. ; Trahms, L. ; Weis, Antoine ; Zejma, J. ; Zenner, J. ; Zsigmond, G.

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...

Université de Fribourg

Production of ultracold neutrons from cryogenic ²H₂, O₂, and C²H₄ converters

Atchison, F. ; Blau, B. ; Bodek, K. ; Brandt, B. van den ; Bryś, T. ; Daum, M. ; Fierlinger, P. ; Geltenbort, P. ; Hautle, P. ; Henneck, R. ; Heule, S. ; Holley, A. ; Kasprzak, Malgorzata ; Kirch, K. ; Knecht, A. ; Konter, J. A. ; Kuźniak, M. ; Liu, C.-Y. ; Pichlmaier, A. ; Plonka, C. ; Pokotilovski, Y. ; Saunders, A. ; Tortorella, D. ; Wohlmuther, M. ; Young, A. R. ; Zejma, J. ; Zsigmond, G.

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...

Université de Fribourg

Test of Lorentz invariance with spin precession of ultracold neutrons

Altarev, I. ; Baker, C. A. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Daum, M. ; Fierlinger, P. ; Geltenbort, P. ; Green, K. ; Grinten, M. G. D. van der ; Gutsmiedl, E. ; Harris, P. G. ; Heil, W. ; Henneck, R. ; Horras, M. ; Iaydjiev, P. ; Ivanov, S. N. ; Khomutov, N. ; Kirch, K. ; Kistryn, S. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Kuchler, F. ; Kuźniak, M. ; Lauer, T. ; Lauss, B. ; Lefort, T. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Pazgalev, Anatoly ; Pendlebury, J. M. ; Petzoldt, G. ; Pierre, E. ; Pignol, G. ; Quéméner, G. ; Rebetez, Martin ; Rebreyend, D. ; Roccia, S. ; Rogel, G. ; Severijns, N. ; Shiers, D. ; Sobolev, Yu. ; Weis, Antoine ; Zejma, J. ; Zsigmond, G.

In: Physical Review Letters, 2009, vol. 103, no. 8, p. 081602

A clock comparison experiment, analyzing the ratio of spin precession frequencies of stored ultracold neutrons and ¹⁹⁹Hg atoms, is reported. No daily variation of this ratio could be found, from which is set an upper limit on the Lorentz invariance violating cosmic anisotropy field b⊥<2×10⁻²⁰ eV (95% C.L.). This is the first limit for the free neutron. This result...