Extension of the VITESS polarized neutron suite towards the use of imported magnetic field distributions

International Workshop on Neutron Optics and Detectors

Manoshin, S.^1 ; Rubtsov, A.^1 ; Bodnarchuk, V.^1 ; Mattauch, S.^2 ; Ioffe, A.^2

Joint Institute of Nuclear Research, Frank Laboratory of Neutron Physics, 141980 Moscow region, Russia^1

Jülich Centre for Neutron Science-Outstation Garching, Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany^2

关键词: 3-dimensional spaces;    Direct measurement;    Latest development;    Magnetic field distribution;    Magnetic field mapping;    Polarized neutrons;    Rotating magnetic fields;    Simulation packages;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/528/1/012033/pdf
DOI  :  10.1088/1742-6596/528/1/012033

来源: IOP

【 摘 要 】

Latest developments of the polarized neutron suite in the VITESS simulation package allowed for simulations of time-dependent spin handling devices (e.g. radio-frequency (RF) flippers, adiabatic gradient RF-flippers) and the instrumentation built upon them (NRSE, SESANS, MIEZE, etc.). However, till now the magnetic field distribution in such devices have been considered as "ideal" (sinusoidal, triangular or rectangular), when the main practical interest is in the use of arbitrary magnetic field distributions (either obtained by the field mapping or by FEM calculations) that may significantly influence the performance of real polarized neutron instruments and is the key issue in the practical use of the simulation packages. Here we describe modified VITESS modules opening the possibility to load the magnetic field 3-dimensional space map from an external source (file). Such a map can be either obtained by direct measurements or calculated by dedicated FEM programs (such as ANSYS, MagNet, Maxwell or similar). The successful use of these new modules is demonstrated by a very good agreement of neutron polarimetric experiments with performance of the spin turner with rotating magnetic field and an adiabatic gradient RF-flipper simulated by VITESS using calculated 3-dimensional field maps (using MagNet) and magnetic field mapping, respectively.