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. 2017-09-19 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. application/pdf https://folia.unifr.ch/global/documents/305992 https://folia.unifr.ch/documents/305992/files/kas_ldu.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevC.96.035205 info:eu-repo/semantics/openAccess License undefined Physical Review C. - 2017, vol. 96, no. 3, p. 035205 info:eu-repo/classification/udc/53 Losses and depolarization of ultracold neutrons on neutron guide and storage materials http://purl.org/coar/resource_type/c_6501