Component Manual for the Neutron Ray-Tracing Package McStas, version 3.8.6

14.61  The Transmission_polarisatorABSnT McStas Component

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

Identification

Description

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

Example: Gravity_guide(w1=0.1, h1=0.1, w2=0.1, h2=0.1, l=12,

R0=0.99, Qc=0.021, alpha=6.07, m=1.0, W=0.003, k=1, d=0.0005)

Example: Transmission_polarisatorABSnT(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,

R0_up=0.99, Qc_up=0.014, alpha_up=2.25, W_up=0.0025, mup=1.0,

R0_down=0.99, Qc_down=0.02174, alpha_down=3.8, W_down=0.00235, mdown=2.5)

Input parameters

Parameters in boldface are required; the others are optional.

Name

Unit

Description

Default

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 wafer

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

R0_up

1

Low-angle reflectivity of the Fe/Si-wafer for spin up neutrons

0.99

Qc_up

Å\(^{-1}\)

Critical scattering vector of the Fe/Si-wafer for spin up neutrons

0.0109

alpha_up

Å

Slope of reflectivity of the Fe/Si-wafer for spin up neutrons

4.25

W_up

Å\(^{-1}\)

Width of supermirror cut-off of the Fe/Si-wafer for spin up neutrons

0.0025

R0_down

1

Low-angle reflectivity of the Fe/Si-wafer for spin down neutrons

0.99

Qc_down

Å\(^{-1}\)

Critical scattering vector of the Fe/Si-wafer for spin down neutrons

0.02174

alpha_down

Å

Slope of reflectivity of the Fe/Si-wafer for spin down neutrons

6.25

W_down

Å\(^{-1}\)

Width of supermirror cut-off of the Fe/Si-wafer for spin down neutrons

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

mup

1

m-value of the Fe/Si-wafer for spin up neutrons

-1

mdown

1

m-value of the Fe/Si-wafer for spin down neutrons

-1

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