Bachelor Thesis

FZJ-2021-05161

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Modellanpassung und Parameterschätzung für Forschung mit Neutronen

Katter, J. (Corresponding author)FZJ*

2021

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

Note: There are many areas in the research with neutrons where model ttingand parameter estimation play a great role. Physical laws that are alreadyexplored, oer models that depend on dierent parameters. Those models canbe used for simulating an experiment, for example by specifying the parame-ters, or those models can be used for estimating the parameters by tting themodel to experimental data.In this work, two sub-areas of neutron research, each with a specic case ofmodel tting and parameter estimation, are examined in more detail.On the one hand, the calculation of the parameter uncertainties in the Levenberg-Marquardt algorithm is considered. The algorithm is used by the softwareSteca to t the data from neutron diraction to a model.Furthermore, the Dierential Evolution Algorithm is looked upon, which isconsidered to be added to the software BornAgain , a software for simulatingand tting X-ray and neutron reectometry, as a further algorithm for pa-rameter estimation. As BornAgain is programmed in C ++ , I discussed thepossibility of accessing the Python implementation of the Dierential Evolu-tion algorithm.
Note: Bachelorarbeit, Hochschule für Angewandte Wissenschaften München, 2021

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Contributing Institute(s):

1. JCNS-FRM-II (JCNS-FRM-II)
2. JCNS-4 (JCNS-4)
3. Heinz Maier-Leibnitz Zentrum (MLZ)

Research Program(s):

1. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)
2. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2021

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