[ 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.

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 |

AT ( | , | , |  | ) RELATIVE |  |
ROTATED ( | , | , |  | ) RELATIVE |

## Links

- Source code for `Guide_tapering.comp`.

[ Identification | Description | Input parameters | Links ]