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Material reflection tables

The tables are from the article

** X-Ray Interactions: Photoabsorption, Scattering, Transmission, and Reflection at E=50-30.000eV, Z=1-92 **

B.L.Henke, E.M.Gullikson and J.C.Davis Center for X-Ray optics, lawrence Berkeley Laboratory, California 94720

link

And from various sources from https://refractiveindex.info/.

When possible, the two sources were merged (for example energies above 30eV are from Henke et al., and energies below from https://refractiveindex.info/)

Material data in SynRad

You can find the data in .csv files in Synrad's param/Materials folder (Gitlab link). SynRad loads all .csv files in this folder on startup. A CSV file has the grazing angles (0 rad = parallel, PI/2 rad = perpendicular) in the top row, and the energy in eV in the first column. The cell values (belonging to a specific angle and energy) are the reflectivity probabilities (from 0 to 1).

You can add your own files here, they will also be discovered when SynRad starts.

Hint

Be careful: SynRad will save the material name with the file, but not the material data, which it expects in the params/Materials folder. If you used custom materials, you have to share the .csv table to open the file on an other SynRad installation. If Synrad doesn't find the material, the GUI will display "invalid material" for the facet reflection type, and you'll get an error message if you try to launch the simulation.

Complex materials

By default, a .csv file (like 02-Copper.csv) has one table with the reflection probability, thus the absorption probability is p_abs = 1 - p_refl.

SynRad can, however, perform other reflection types as well:

  • Forward reflection: the "classic" mirror-like (or specular) reflection
  • Diffuse scattering: a new direction is generated randomly following the Cosine distriubtion (Lambertian reflector)
  • Backscattering: the ray is turned back (and perturbated if the surface is rough) - used to model sawtooth surfaces where a part of the photons scatters back. See an example in section 2.5.1.1 (sawtooth surfaces) in my thesis.
  • Transparent pass: the ray crosses the surface

As in the example of 13-Iron_rough_sawtooth.csv, you can see four tables following each other: one for each reflection type. There are no empty rows in between, and the header (top) row with the angles is only included with forward reflection (writing angles to the diffuse or back-scattering will be ignored). The cell values in the four tables (that must to be present, even if with 0 probabilities) give...

  • p_forward
  • p_diffuse
  • p_back
  • p_transp

probabilities and

p_absorption = 1 - p_forward - p_diffuse - p_back - p_transp

Examples of materials included in SynRad

Aluminium

aluminium

Aluminium-oxide

al2o3

Copper

copper

Gold

gold

Iron

iron

Tantalum

tantalum

Last update: March 28, 2025