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

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

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,...

Université de Fribourg

Testing isotropy of the universe using the Ramsey resonance technique on ultracold neutron spins

Altarev, I. ; Ban, G. ; Bison, Georg ; Bodek, K. ; Daum, M. ; Fertl, M. ; Fierlinger, P. ; Franke, B. ; Gutsmiedl, E. ; Heil, W. ; Henneck, R. ; Horras, M. ; Khomutov, N. ; Kirch, K. ; Kistryn, S. ; Kraft, A. ; Knecht, A. ; Knowles, Paul E. ; Kozela, A. ; Lauer, T. ; Lauss, B. ; Lefort, T. ; Lemière, Y. ; Mtchedlishvili, A. ; Naviliat-Cuncic, O. ; Pazgalev, Anatoly S. ; Petzoldt, G. ; Piegsa, F.M. ; Pierre, E. ; Pignol, G. ; Quéméner, G. ; Rebetez, M. ; Rebreyend, D. ; Roccia, S. ; Schmidt-Wellenburg, P. ; Severijns, N. ; Sobolev, Yu. ; Weis, Antoine ; Zejma, J. ; Zenner, J. ; Zsigmond, G.

In: Physica B: Condensed Matter, 2011, vol. 406, no. 12, p. 2365-2369

Physics at the Planck scale could be revealed by looking for tiny violations of fundamental symmetries in low energy experiments. In 2008, a sensitive test of the isotropy of the universe has been performed with stored ultracold neutrons (UCN), this is the first clock-comparison experiment performed with free neutrons. During several days we monitored the Larmor frequency of neutron spins in a...

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

MC calculations for the nEDM experiment systematics

Bodek, K. ; Chowdhuri, Z. ; Daum, M. ; Fertl, M. ; Franke, B. ; Gutsmiedl, E. ; Henneck, R. ; Horras, M. ; Kasprzak, Malgorzata ; Kirch, K. ; Kistryn, S. ; Kozela, A. ; Krempel, J. ; Lauss, B. ; Mtchedlishvili, A. ; Piegsa, F. ; Pignol, G. ; Rebreyend, D. ; Roccia, S. ; Schmidt-Wellenburg, P. ; Zejma, J. ; Zenner, J. ; Zsigmond, G.

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...

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...

Université de Fribourg

Neutron to mirror-neutron oscillations in the presence of mirror magnetic fields

Altarev, I. ; Baker, C. A. ; Ban, G. ; Bodek, K. ; Daum, M. ; Fierlinger, P. ; Geltenbort, P. ; Green, K. ; Grinten, M. G. D. van der ; Gutsmiedl, E. ; Harris, P. G. ; Henneck, R. ; Horras, M. ; Iaydjiev, P. ; Ivanov, S. ; 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. ; Paul, S. ; Pazgalev, Anatoly ; Pendlebury, J. M. ; Petzoldt, G. ; Pierre, E. ; Plonka-Spehr, C. ; Quéméner, G. ; Rebreyend, D. ; Roccia, S. ; Rogel, G. ; Severijns, N. ; Shiers, D. ; Sobolev, Yu. ; Stoepler, R. ; Weis, Antoine ; Zejma, J. ; Zenner, J. ; Zsigmond, G.

In: Physical Review D, 2009, vol. 80, no. 3, p. 032003

We performed ultracold neutron storage measurements to search for additional losses due to neutron (n) to mirror-neutron (n') oscillations as a function of an applied magnetic field B. In the presence of a mirror magnetic field B', ultracold neutron losses would be maximal for B~B'. We did not observe any indication for...