Application of a Portable $^3$He-Based Polarization Insert at a Time-of-Flight Neutron Reflectometer

Wolfgang Kreuzpaintner; Sergey Masalovich; Jean-François Moulin; Birgit Wiedemann; Jingfan Ye; Sina Mayr; Amitesh Paul; Martin Haese; Matthias Pomm; Peter Böni

doi:10.1016/j.nima.2016.12.017

arXiv · 1604.00816

Application of a Portable $^3$He-Based Polarization Insert at a Time-of-Flight Neutron Reflectometer

Wolfgang Kreuzpaintner·Sergey Masalovich·Jean-François Moulin·Birgit Wiedemann·Jingfan Ye·Sina Mayr·Amitesh Paul·Martin Haese·Matthias Pomm·Peter Böni

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Abstract

The suitability of a transportable 3He-spin filter as temporary broadband polarizer for a Time-of-Flight neutron reflectometer is demonstrated. A simple two-wavelength method for characterisation of a 3He-spin filter is proposed, which can be applied even if the absolute transmittance of the 3He-spin filter cannot be accurately determined. We demonstrate the data treatment procedure for extracting the spin-up and spin-down neutron reflectivity from measurements obtained with a time dependent 3He polarization. The extraction of a very weak magnetic signal from reflectivity data, measured on the in-situ grown magnetic heterostructure Fe1 nm/Cu20 nm/Sisubstrate in an externally applied magnetic field of 30mT is presented and compared to similar measurements on the growth stage Cu20 nm/Sisubstrate of the very same sample, which does not yet contain any magnetic material.

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Wolfgang Kreuzpaintner, Sergey Masalovich, Jean-François Moulin, Birgit Wiedemann, Jingfan Ye, Sina Mayr, Amitesh Paul, Martin Haese, Matthias Pomm, Peter Böni. 2017-03-03. Application of a Portable $^3$He-Based Polarization Insert at a Time-of-Flight Neutron Reflectometer. https://doi.org/10.1016/j.nima.2016.12.017

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