McStas logo McStas - A neutron ray-trace simulation package ILL; PSI; ESS Niels Bohr Institute DTU Physics NEXMAP

McStas

About McStas
 Conditions of use
 Authors/Contacts
 Project funding

Download
 Components
 Other Downloads (share)

Mailing list

Search web/mailinglist

Documentation
 Wiki (GitHub)
 McStas manual
 Publications

Links

Report bugs (GitHub)

Code-repository (GitHub)


McStas: Guide_tapering

[ Identification | Description | Input parameters | Links ]

The Guide_tapering Component

Models a rectangular tapered guide (many shapes)

Identification

  • Site:
  • Author: Uwe Filges
  • Origin: PSI
  • Date: 22/10/2003

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.
NameUnitDescriptionDefault
optionstrdefine 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 walls0
w1mWidth at the guide entry0
h1mHeight at the guide entry0
lmlength of guide
linwmdistance from 1st focal point to real guide entry - left and right horizontal mirrors0
loutwmdistance from real guide exit to 2nd focal point - left and right horizontal mirrors0
linhmdistance from 1st focal point to real guide entry - top and bottom vertical mirrors0
louthmdistance from real guide exit to 2nd focal point - top and bottom vertical mirrors0
R01Low-angle reflectivity0.99
QcxAA-1Critical scattering vector for left and right vertical mirrors in each channel0.021
QcyAA-1Critical scattering vector for top and bottom mirrors0.021
alphaxAASlope of reflectivity for left and right vertical mirrors in each channel6.07
alphayAASlope of reflectivity for top and bottom mirrors6.07
WAA-1Width of supermirror cut-off for all mirrors0.003
mx1m-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/w1
my1m-value of material for top and bottom mirrors. Zero means completely absorbing. Negative value will adapt coating as e.g. m=my*h1/h1
segno1number of segments (z-axis) for cutting the tube800
curvaturemguide horizontal radius of curvature. Zero means straight.0
curvature_vmguide vertical radius of curvature. Zero means straight.0
AT ( , , ) RELATIVE
ROTATED ( , , ) RELATIVE

Links


[ Identification | Description | Input parameters | Links ]

Generated on 2024-01-03 11:47:43


Last Modified: Wednesday, 03-Jan-2024 19:59:11 CET
Search website mailinglist archive GitHub repos