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McStas: Guide_tapering Component

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

The Guide_tapering Component

Models a rectangular tapered guide (many shapes)

Identification

  • Author: Uwe Filges
  • Origin: PSI
  • Date: 22/10/2003
  • Version:(Unknown)
  • Modification history:
    • Rob Dalgliesh, ISIS, 2007

Description

Models a rectangular guide tube centered on the Z axis. The entrance lies
in the X-Y plane.
The guide may be tapered.

The component includes a feature to read in self-defined functions for
guide tapering. Under the parameter 'option' the KEYWORD 'file=' offers
the possibility to read in parameters from an ASC-file. The file structure
is shown below in the example. It is important to know that the first
3 lines will be interpreted as comments.
Afterwards the dimension of each guide segment must be defined. The
length of each segment is constant l(i)=l/segments . The number of
segments is defined through the number of lines minus the first 3
lines taken from the Input-File.
The guide can be made curved both horizontally and vertically (not shown in 3d
view), and m-coating, when set negative, is varied in 1/width.

Example Input-File:

c Guide_tapering.comp
c i = 0 - 199 segments
c h1(i)     h2(i)   w1(i)    w2(i)
0.120000 0.119850 0.020000 0.020000
0.119850 0.119700 0.020000 0.020000
0.119700 0.119550 0.020000 0.020000
0.119550 0.119400 0.020000 0.020000
0.119400 0.119250 0.020000 0.020000
0.119250 0.119100 0.020000 0.020000
...

Example1: Guide_tapering(w1=0.1, h1=0.18, linw=0.1, loutw=0.1, linh=0.1, louth=0.1, l=1.5, option="elliptical", R0=0.99, Qcx=0.021, Qcy=0.021, alphax=6.07, alphay=6.07, W=0.003, mx=1, my=1, segno=800)

Example2: Guide_tapering(w1=0, h1=0, linw=0, loutw=0, linh=0, louth=0, l=1.5, option="file=ownfunction.txt", R0=0.99, Qcx=0.021, Qcy=0.021, alphax=6.07, alphay=6.07, W=0.003, mx=1, my=1)

%BUGS
This component does not work with gravitation on. Use component Guide_gravity then.

Input parameters

Parameters in boldface are required; the others are optional.
Name Unit Description Default
option str define the input function for the curve of the guide walls options are: "elliptical" - define elliptical function of guide walls "parabolical" - define parabolical function of guide walls "straight" - define a straight elements guide"file=[filename]" - read in ASC-file with arbitrary definition for the curve of the guide walls 0
w1 m Width at the guide entry 0
h1 m Height at the guide entry 0
l m length of guide  
linw m distance from 1st focal point to real guide entry - left and right horizontal mirrors 0
loutw m distance from real guide exit to 2nd focal point - left and right horizontal mirrors 0
linh m distance from 1st focal point to real guide entry - top and bottom vertical mirrors 0
louth m distance from real guide exit to 2nd focal point - top and bottom vertical mirrors 0
R0 1 Low-angle reflectivity 0.99
Qcx AA-1 Critical scattering vector for left and right vertical mirrors in each channel 0.021
Qcy AA-1 Critical scattering vector for top and bottom mirrors 0.021
alphax AA Slope of reflectivity for left and right vertical mirrors in each channel 6.07
alphay AA Slope of reflectivity for top and bottom mirrors 6.07
W AA-1 Width of supermirror cut-off for all mirrors 0.003
mx 1 m-value of material for left and right vertical mirrors in each channel. Zero means completely absorbing. Negative value will adapt coating as e.g. m=mx*w1/w 1
my 1 m-value of material for top and bottom mirrors. Zero means completely absorbing. Negative value will adapt coating as e.g. m=my*h1/h 1
segno 1 number of segments (z-axis) for cutting the tube 800
curvature m guide horizontal radius of curvature. Zero means straight. 0
curvature_v m guide vertical radius of curvature. Zero means straight. 0

Links


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

Generated automatically by McDoc, Peter Willendrup <peter.willendrup@risoe.dk> / Fri May 7 10:17:14 2021


Last Modified: Friday, 07-May-2021 12:17:14 CEST
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