14.57  The Foil_flipper_magnet McStas Component

A magnet with a spin-flip foil inside

Identification

• Author: Erik B Knudsen

• Origin: DTU Physics

• Date: Sep. 2015

Description

ESCRIPTION A magnet with a spin-flip foil inside

This component models a magnet with a constant magnetic field and a slanted magnetized foil inside acting as a spin-flipper. This arrangement may be used to target the geometry of a Spin-Echo SANS instrument (Rekveldt, NIMB, 1997 || Rekveldt, Rev Sci Instr. 2005). In its most basic form a SE-SANS instrument nrelies on inclined field regions of constant magnetic field, which can be difficult to realize. Instead it is possible to emulate such regions using a magnetized foil.

In this component th emagntzied foil is modelled as a canted (by the angle phi) mathematical plane inside a region of constant magnetic field of dimensions (xwidth,yheight,zdepth). Furthermore, exponetially decaying stray fields from the constant field region may be specified by giving parameters (Bxwidth,Byheight,Bzdepth) > (xwidth,yheight,zdepth).

Input parameters

Parameters in boldface are required; the others are optional.

Links

• Component source code found in file Foil_flipper_magnet.comp.