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

# The `Guide_tapering` Component

Models a rectangular tapered guide (many shapes)

## Identification

- Author: Uwe Filges
- Origin: McStas 1.6
- Date: 22/10/2003
- Version: 1.6

## 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.

    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.

WARNING: This is a contributed Component.

## 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 "file=[filename]" - read in ASC-file with arbitrary definition for the curve of the guide walls | 0
segno | 1 | number of segments (z-axis) for cutting the tube | 800
w1 | m | Width at the guide entry | 0
h1 | m | Height at the guide entry | 0
l | m | length of guide |
linw | m | distance of 1. focal point and real guide entry - left and right horizontal mirrors | 0
loutw | m | distance of real guide exit and 2nd focal point - left and right horizontal mirrors | 0
linh | m | distance of 1st focal point and real guide entry - top and bottom vertical mirrors | 0
louth | m | distance of real guide exit and 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. | 1
my | 1 | m-value of material for top and bottom mirrors. Zero means completely absorbing. | 1

## Output parameters

Name | Unit | Description | Default
--- | --- | --- | ---
w1c |  |  |
w2c |  |  |
ww |  |  |
hh |  |  |
whalf |  |  |
hhalf |  |  |
lwhalf |  |  |
lhhalf |  |  |
h1_in |  |  |
h2_out |  |  |
w1_in |  |  |
w2_out |  |  |
l_seg |  |  |

## Links

- Source code for `Guide_tapering.comp`.

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