X-ray compound refractive lens (CRL) with a profile of the parabola
Author: Jana Baltser and Erik Knudsen
Origin: NBI
Date: August 2010, modified July 2011
A simple X-ray compound refractive lens (CRL) with a profile of the parabola in rotation simulates the photons’ movement on passing through it. The CRL focuses in 2D
Example: Lens_parab(material_datafile = ”Be.txt”, r=200e-6, r_ap=0.5e-3, d=50e-6, N=16)
Parameters in boldface are required; the others are optional.
|
Name |
Unit |
Description |
Default |
|
|
|||
|
material_datafile |
str |
Datafile containing f1 constants |
”Be.txt” |
|
r |
m |
Radius of curvature (circular approximation at the tip of the profile). |
0.5e-3 |
|
r_ap |
m |
Radius of circular aperture, which also defines the depth of the lens profile. |
1.4e-3 |
|
d |
m |
Distance between two surfaces of the lens along the propagation axis. |
.1e-3 |
|
N |
m |
Number of single lenses in a stack. |
1 |
|
rough_z |
rad |
RMS value of random slope error along z. |
0 |
|
rough_xy |
rad |
RMS value of random slope error along x and y. |
0 |
|
|
|||
|
|
|||
|
|
|||
Component source code found in file Lens_parab.comp.
Component model of a stack of compund refractive lenses. Each lens in the stack is modelled by two \(2D\) parabolic surfaces, and rays are traced through all the complete stack taking the displacement of the surfaces into account. This is naturally less efficient than a thin lens approximation.
The logic behind the model is the following: a photon interacts with the surface of the lens at a certain angle \(\Theta \), which alters in accordance with Snell’s law upon photon’s entering the lens’s material. The combination of the refractive process inside material (that is characterized by a material datafile) and the interaction with a geometrical surface results in a photon’s new trajectory, i.e. in focusing.
The functionality of Lens_parab_Cyl, Lens_parab_rough, and Lens_parab_Cyl_rough will be merged into this component.