How to polarise all neutrons in one beam: a high performance polariser and neutron transport system

6th European Conference on Neutron Scattering

Rodriguez, D. Martin^1 ; Bentley, P.M.^1,3 ; Pappas, C.^2

European Spallation Source ESS ERIC, Box 176, Lund

221 00, Sweden^1

Faculty of Applied Sciences, Delft University of Technology, Netherlands^2

Department of Physics and Astronomy, University of Uppsala, Uppsala

751 20, Sweden^3

关键词: Neutron transport;    Polarised neutrons;    Polarisers;    Sample position;    Soft matter;    Spin direction;    Spin state;    Wavelength ranges;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/746/1/012015/pdf
DOI  :  10.1088/1742-6596/746/1/012015

来源: IOP

【 摘 要 】

Polarised neutron beams are used in disciplines as diverse as magnetism,soft matter or biology. However, most of these applications often suffer from low flux also because the existing neutron polarising methods imply the filtering of one of the spin states, with a transmission of 50% at maximum. With the purpose of using all neutrons that are usually discarded, we propose a system that splits them according to their polarisation, flips them to match the spin direction, and then focuses them at the sample. Monte Carlo (MC) simulations show that this is achievable over a wide wavelength range and with an outstanding performance at the price of a more divergent neutron beam at the sample position.