The Transmission_V_polarisator McStas Component

Transmission V-polarisator including absorption by Fe in the supermirror. Experimentally benchmarked.

Transmission V-polarisator including absorption by Fe in the supermirror.

Example: Transmission_V_polarisator(w1=0.050, h1=0.050,

w2=0.050, h2=0.050, l=2.700,
waferD=0.0003, FeD=2.16e-06,
Si_i=0.2, Si_a=0.215,
R0=0.99, Qc=0.02174, alpha=4.25, W=0.001,

mleft=1.2, mright=1.2, mtop=1.2, mbottom=1.2, reﬂectUP="measured_up_q.dat",reﬂectDW="measured_dw_q.dat")

Parameters in boldface are required; the others are optional.


Name	Unit	Description	Default



reﬂectUP	str	Reﬂectivity proﬁle of the FeSi-wafer for spin-up neutrons; columns [q,R]	0
reﬂectDW	str	Reﬂectivity proﬁle of the FeSi-wafer for spin-down neutrons; columns [q,R]	0
w1	m	Width at the polarizer entry
h1	m	Height at the polarizer entry
w2	m	Width at the polarizer exit
h2	m	Height at the polarizer exit
l	m	length of polarizer
waferD	m	Thickness of Si wafer
Si_i	barns	Scattering cross section per atom (barns)
Si_a	barns	Absorption cross section per atom (barns) at 2200m/s
FeD	m	Thickness of Fe in supermirror, Ti is neglected
R0	1	Low-angle reﬂectivity of the outer guide	0.99
Qc	Å\(^{-1}\)	Critical scattering vector of the outer guide	0.02174
alpha	Å	Slope of reﬂectivity of the outer guide	4.25
W	Å\(^{-1}\)	Width of supermirror cut-oﬀ of the outer guide	0.001
mleft	1	m-value of material for left. vert. mirror of the outer guide	-1
mright	1	m-value of material for right. vert. mirror of the outer guide	-1
mtop	1	m-value of material for top. horz. mirror of the outer guide	-1
mbottom	1	m-value of material for bottom. horz. mirror of the outer guide	-1