Journal Article

IMPULSE-2025-00107

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Depolarization studies on low-depolarizing Cu/Ti and Ni(Mo)/Ti neutron supermirrors

Gomez, J. (Corresponding author)MLZ* ; Bernert, K. ; Devishvili, A. ; Klauser, C. ; Märkisch, B. ; Schmidt, U. ; Soldner, T.

2025
Elsevier [Amsterdam]

Please use a persistent id in citations: doi:10.1016/j.nima.2025.170795

Abstract: Neutron supermirrors are a crucial part of many scattering and particle physics experiments. So far, Ni(Mo)/Ti supermirrors have been used in experiments that require to transport a polarized neutron beam due to their lower saturation magnetization compared to Ni/Ti supermirrors. However, next generation decay experiments require supermirrors that depolarize below per reflection to reach their targeted precision. The depolarization of a polarized neutron beam due to reflection off Ni(Mo)/Ti supermirrors has not yet been measured to that precision. Recently, Cu/Ti supermirrors with a lower saturation magnetization compared to Ni(Mo)/Ti have been developed, and may serve as an alternative. In this paper, we test the performance of both mirrors. At a first stage, we present four-states polarized neutron reflectivity curves of Ni(Mo) and Cu monolayers and Ni(Mo)/Ti and Cu/Ti supermirrors measured at the neutron reflectometer SuperADAM and perform a full polarization analysis, with the aim to extract information about their magnetic moment. The results found, however, were inconclusive, since it seems a detection limit of this method for all measured samples was reached. At a second stage, we measured the depolarization () that a polarized neutron beam suffers after reflection off the same Ni(Mo)/Ti and Cu/Ti supermirrors by using the Opaque Test Bench setup. We find upper limits for the depolarization of , , and at the confidence level, where (4N5) corresponds to a Ti purity of and (2N6) to . These results show that all three supermirrors are suitable for being used in next generation decay experiments. We found no noticeable dependence of the depolarization on the value or the magnetizing field, in which the samples were placed.

Keyword(s): Instrument and Method Development (1st) ; Instrument and Method Development (2nd)

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Contributing Institute(s):

1. OPTIC (OPTIC)

Research Program(s):

1. DFG project G:(GEPRIS)390783311 - EXC 2094: ORIGINS: Vom Ursprung des Universums bis zu den ersten Bausteinen des Lebens (390783311) (390783311)

Experiment(s):

1. Measurement at external facility

Appears in the scientific report 2025

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Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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