About McXtrace
Publications
Project Partners
Project People
Goal
Documentation
Manual
Commands
Wiki (GitHub)
Tutorial
5.1 The Lens_simple McXtrace Component
Simple refractive x-ray lens
Identification
-
Author: Erik Knudsen
-
Origin: Risoe
-
Date: June 16, 2009
Description
Models a stack of N refractive lenses, with a radius of curvature, r, at the apex. The model is a thin-lens approximation where photons are refracted in a the XY plane at Z=0. Absorption is generally disregarded may be handled through the use of the optional transmission parameter T, where 0<=T<=1. Thus, the lens has the focal length of f=R/(2*N*&delta) where the x-ray refractive index is written: n = 1 - &delta + i &beta.
Example: Lens_simple(xwidth=1e-5, yheight=1e-5, material_datafile=”Be.txt”,N=100,r=0.3e-3)
Input parameters
Parameters in boldface are required; the others are optional.
|
Name |
Unit |
Description |
Default |
|
|
|||
|
xwidth |
m |
Width of lens aperture. |
0 |
|
yheight |
m |
Height of lens aperture. |
0 |
|
radius |
m |
Radius of lens aperture (overrides xwidth & yheight). |
1e-3 |
|
T |
0-1 |
Transmission efficiency of the lens. |
1 |
|
r |
m |
The radius of curvature of the lens. Optional parameters: |
3e-4 |
|
N |
1 |
The number of successive lenses in the stack. |
1 |
|
verbose |
0/1 |
Extra information for debugging. |
0 |
|
f |
m |
Focal length - overrides the material_datafile - and diregards chromatic aberration. |
0 |
|
material_datafile |
|
File where the material parameters for the lens may be found. Format is similar to what may be found off the NIST website. |
”Be.txt” |
|
|
|||
|
|
|||
|
|
|||
Links
-
Component source code found in file Lens_simple.comp.
-
material datafile obtained from http://physics.nist.gov/cgi-bin/ffast/ffast.pl
Thin lens approximation
This models a thin-lens approximation of a stack of parabolic refractive x-ray lenses
