Neutron guide with gravity and honeycomb geometry. Can be channeled and focusing.
Author: G. Venturi
Origin: <a href="http://www.ill.fr">ILL (France)</a>.
Date: Apr 2003
Models a honeycomb guide tube centered on the Z axis. The entrance lies in the X-Y plane. Gravitation applies also when reaching the guide input window. The guide can be channeled (hexagonal channel section; nslit,d parameters). The guide coating specifications may be entered via different ways (global, or for each wall m-value). For details on the geometry calculation see the description in the McStas reference manual.
Example: Guide_honeycomb(w1=0.1, w2=0.1, l=12,
R0=0.99, Qc=0.0219, alpha=6.07, m=1.0, W=0.003, nslit=1, d=0.0005)
Parameters in boldface are required; the others are optional.
|
Name |
Unit |
Description |
Default |
|
|
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|
w1 |
m |
Width at the guide entry |
|
|
w2 |
m |
Width at the guide exit. If zero, sets w2=w1. |
0 |
|
l |
m |
length of guide |
|
|
R0 |
1 |
Low-angle reflectivity |
0.995 |
|
Qc |
Å\(^{-1}\) |
Critical scattering vector |
0.0218 |
|
alpha |
Å |
Slope of reflectivity |
4.38 |
|
m |
1 |
m-value of material. Zero means completely absorbing. |
1.0 |
|
W |
Å\(^{-1}\) |
Width of supermirror cut-off |
0.003 |
|
nslit |
1 |
Number of horizontal channels in the guide (>= 1) [1] |
1 |
|
d |
m |
Thickness of subdividing walls [0] |
0.0005 |
|
mleftup |
1 |
m-value of material for leftup. oblique mirror |
-1 |
|
mrightup |
1 |
m-value of material for rightdown. oblique mirror |
-1 |
|
mleftdown |
1 |
m-value of material for rightdown. oblique mirror |
-1 |
|
mrightdown |
1 |
m-value of material for leftup. oblique mirror |
-1 |
|
mleft |
1 |
m-value of material for left. vertical mirror |
-1 |
|
mright |
1 |
m-value of material for right. vertical mirror |
-1 |
|
G |
m/s\(^{2}\) |
Gravitation norm. 0 value disables G effects. |
0 |
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Component source code found in file Guide_honeycomb.comp.