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McStas: Guide_honeycomb Component

[ Identification | Description | Input parameters | Output parameters | Links ]

The Guide_honeycomb Component

Neutron guide with gravity and honeycomb geometry. Can be channeled and focusing.


  • Author: G. Venturi
  • Origin: ILL (France).
  • Date: Apr 2003
  • Version: $Revision$
  • Modification history:
    • G. Venturi, Made Honeycomb from Guide_gravity (Apr 2003)
    • E. Farhi, corrected gravitation bug (Feb 2005)
    • E. Farhi, uniformize parameter names (Jul 2008)


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)

Example values: m=4 Qc=0.02 W=1/300 alpha=6.49 R0=1

WARNING: This is a contributed Component.

Input parameters

Parameters in boldface are required; the others are optional.
Name Unit Description Default
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 AA-1 Critical scattering vector 0.0218
alpha AA Slope of reflectivity 4.38
m 1 m-value of material. Zero means completely absorbing. 1.0
W AA-1 Width of supermirror cut-off 0.003
nslit nslit-1 vertical dividing walls [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/s2 Gravitation norm. 0 value disables G effects. 0

Output parameters

Name Unit Description Default
GVars - .N_reflection: (1) Array of the cumulated Number of reflections N_reflection[0] total nb of reflections N_reflection[1,2,3,4.5.6] reflections N_reflection[7] total nb neutrons exiting guide N_reflection[8] total nb neutrons entering guide  


[ Identification | Description | Input parameters | Output parameters | Links ]

Generated automatically by McDoc, Peter Willendrup <> / Fri Mar 17 20:40:06 2017

Last Modified: Friday, 17-Mar-2017 21:40:06 CET
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