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.

doi:10.1103/PhysRevC.96.035205

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Journal article

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

Bondar, V. Paul Scherrer Institute (PSI), Villigen PSI, Switzerland - Kyiv Polytechnic Institute (KPI), Kyiv, Ukraine
Chesnevskaya, S. Physik Department, Technische Universität München (TUM), Garching, Germany
Daum, M. Paul Scherrer Institute (PSI), Villigen PSI, Switzerland
Franke, B. Paul Scherrer Institute (PSI), Villigen PSI, Switzerland - IPP, Institut für Teilchenphysik, ETH Zürich, Switzerland
Geltenbort, P. Institut Laue-Langevin (ILL), Grenoble, France
Göltl, L. Paul Scherrer Institute (PSI), Villigen PSI, Switzerland
Gutsmiedl, E. Physik Department, Technische Universität München (TUM), Garching, Germany
Karch, J. Institut für Physik, Johannes Gutenberg University, Mainz, Germany
Kasprzak, Malgorzata Physics Department, University of Fribourg, Switzerland
Kessler, G. Physik Department, Technische Universität München (TUM), Garching, Germany
Kirch, K. Paul Scherrer Institute (PSI), Villigen PSI, Switzerland - IPP, Institut für Teilchenphysik, ETH Zürich, Switzerland
Koch, Hans-Christian Institut für Physik, Johannes Gutenberg University, Mainz, Germany
Kraft, Andreas Institut für Physik, Johannes Gutenberg University, Mainz, Germany
Lauer, Thorsten Institut für Physik, Johannes Gutenberg University, Mainz, Germany
Lauss, B. Paul Scherrer Institute (PSI), Villigen PSI, Switzerland
Pierre, E. Paul Scherrer Institute (PSI), Villigen PSI, Switzerland - Laboratoire de Physique Corpusculaire (LPC), Caen, France
Pignol, G. Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble-Alpes, France
Reggiani, D. Paul Scherrer Institute (PSI), Villigen PSI, Switzerland
Schmidt-Wellenburg, P. Paul Scherrer Institute (PSI), Villigen PSI, Switzerland
Sobolev, Yuri Institut für Physik, Johannes Gutenberg University, Mainz, Germany
Zechlau, T. Institut für Physik, Johannes Gutenberg University, Mainz, Germany
Zsigmond, G. Paul Scherrer Institute (PSI), Villigen PSI, Switzerland

19.09.2017

Published in:

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

English 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 samples, storage-time constants up to ∼460s were obtained at room temperature. The corresponding loss parameters for ultracold neutrons, η, varied between 1.0×10−4 and 2.2×10−4. All η values are in agreement with theory except for dPS, where anomalous losses at room temperature were established with four standard deviations. The depolarization probabilities per wall collision β measured with unprecedented sensitivity varied between 0.7×10−6 and 9.0×10−6. Our depolarization result for copper differs from other experiments by 4.4 and 15.8 standard deviations. The β values of the paramagnetic NiMo alloys over molybdenum content show an increase of β with increasing Mo content. This is in disagreement with expectations from literature. Finally, ferromagnetic behavior of NiMo alloys at room temperature was found for molybdenum contents of 6.5 at.% or less and paramagnetic behavior for more than 8.7 at.%. This may contribute to solving an ambiguity in literature.

Faculty

Faculté des sciences et de médecine

Department

Département de Physique

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