Université de Fribourg

Study of ³He Rabi nutations by optically-pumped cesium magnetometers

Koch, Hans-Christian ; Bison, Georg ; Grujiæ, Zoran Dragan ; Heil, Werner ; Kasprzak, Malgorzata ; Knowles, Paul ; Kraft, Andreas ; Pazgalev, Anatoly ; Schnabel, Allard ; Voigt, Jens ; Weis, Antoine

In: The European Physical Journal D, 2017, vol. 71, no. 10, p. 262

We describe a method for recording the Rabi nutation of nuclear spin polarized ³He by optically pumped cesium magnetometers. The measurement is performed by detecting the time-dependent magnetic field produced by the 3He magnetization. The observed signals are compared to theoretical models and the results are used to precisely trace the evolution of the magnetization. This procedure...

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

Investigation of the intrinsic sensitivity of a ³He/Cs magnetometer

Koch, Hans Christian ; Bison, Georg ; Grujić, Zoran D. ; Heil, Werner ; Kasprzak, Malgorzata ; Knowles, Paul ; Kraft, Andreas ; Pazgalev, Anatoly ; Schnabel, Allard ; Voigt, Jens ; Weis, Antoine

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...

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

Design and performance of an absolute 3He/Cs magnetometer

Koch, Hans-Christian ; Bison, Georg ; Grujić, Zoran D. ; Heil, Werner ; Kasprzak, Malgorzata ; Knowles, Paul ; Kraft, Andreas ; Pazgalev, Anatoly ; Schnabel, Allard ; Voigt, Jens ; Weis, Antoine

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...

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).