Journal Article

IMPULSE-2021-00343

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Incoherent approximation for neutron up-scattering cross sections and its corrections for slow neutrons and low crystal temperatures

Döge, S. (Corresponding author) ; Liu, C.-Y. ; Young, A. ; Morkel, C.MLZ*

2021
APS College Park, MD, USA

Please use a persistent id in citations: doi:10.1103/PhysRevC.103.054606

Abstract: The incoherent approximation (IA) is often used for calculating the one-phonon inelastic neutron scattering cross section for arbitrary solids. It is valid for thermal neutrons but for slow neutrons it requires a correction, which is significant for isotopes that are strong coherent scatterers. In this article, we present the extension of the Placzek–Van Hove corrections for slow neutrons in the limit of low temperatures using the example of solid ortho-deuterium (sD2). Our approach yields realistic one-phonon up-scattering cross sections for sD2 and shows the IA to be a factor of 2–5 too high for ultracold neutron (UCN) up-scattering in sD2. Our calculations are compared with previously published Monte Carlo calculations of the one-phonon cross section based on the dynamic structure function S(q,omega) of polycrystalline ortho-deuterium and are found to be consistent with them. Furthermore, we provide the means for easily replicable calculations of the one-phonon up-scattering cross sections of solid ortho-deuterium for slow neutrons. These should from now on be used in calculations and simulations of UCN scattering in sD2.

Keyword(s): Nuclei and Particles (1st) ; Instrument and Method Development (2nd) ; Nuclear Physics (2nd) ; Condensed Matter Physics (2nd)

Note: ISSN 2469-9993 not unique: **2 hits**.

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Contributing Institute(s):

1. E21 (E21)
2. E18 (E18)
3. Объединенный институт ядерных исследований (JINR ; ОИЯИ)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2021

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

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