Table 1. Parameters for the SHADOW ray-tracing simulations of the polarization state of the I20-scanning wiggler.

Electron energy	3.0 GeV
R.m.s. horizontal electron beam width	121.62 µm
R.m.s. vertical electron beam width	3.56 µm
Horizontal emittance	2.6 nm rad
Vertical emittance	8.0 pm rad
Wiggler upstream from electron beam waist by	7.5 cm
Number of periods in wiggler	24
Length of wiggler period	83 mm
Wiggler gap	20 mm
Wiggler deflection parameter	9.303
Wiggler magnetic field	1.2 T
Horizontal primary slit width	0.67 mrad
Vertical primary slit width	0.11 mrad
Number of simulated rays	500 000