This Matlab toolbox calculates the refraction properties of a matter under X-ray radiation (energy range 0.03~30 KeV), such as dispersion, absorption parts of the index of refraction, the critical angle of total external reflection, attenuation length etc. It basically does the same thing as CXRO X-Ray Interactions With Matter. However, the advantage is that the toolbox does not require internet access, and you can directly use it in your Matlab script.
Caution: CXRO includes Compton scattering when calculating the absorption length, while Refrac does not. The difference becomes obvious for materials of light elements when energy is >10 Kev.
For example, the following script plots dispersion and absorption of SiO2 for X-ray energies between 0.1-10 KeV:
x = 10.^linspace(log10(0.1), log10(10), 1000); % list of X-ray energies (KeV)
y = refrac('SiO2', x, 2.648); % give chemical formula and mass density to calculate properties of SiO2
loglog(x*1000, y.dispersion, x*1000, y.absorption); % plot in eV
This standalone toolbox is included in GIXSGUI toolbox. However, you can download and run it separately. After downloading, remember to choose "Add with Subfolders" in Matlab "Set Path" to include the main and all subfolders to Matlab search path; otherwise, the toolbox will not work.
For more information about X-ray interactions with matter, go to NIST and LBL.
For usage, in Matlab command window, type ">>help refrac".
refrac Material property when interacting with x-rays.
Usage: result = refrac(Chemical Formula,Energy,MassDensity)
Input:
1) Chemical formula. Can be either cell array (for multiple
formulas) or single string. Formula is case sensitive (e.g. CO
for Carbon Monoxide vs Co for Cobalt);
2) Energy (0.03KeV~30KeV). Can be single or list.
3) List of mass densities (g/cm^3);
Output: Can be either cell of structures (if input formular is cell
array) or single structure (if input is single string) with the
following elements:
1) Chemical formula;
2) Molecular weight;
3) Number of electrons per molecule;
4) Mass density (g/cm^3);
5) Electron density (1/A^3);
6) X-ray energy (KeV);
7) Corresponding X-ray wavelength (A);
8) Dispersion;
9) Absorption;
10) Critical angle (degree);
11) Attenuation length (cm);
12) Real part of scattering length density (SLD) (A^-2);
13) Imaginary part of SLD (A^-2).
Example 1: >> result=refrac({'H2O','Si3N4'},8.04778,[1,3.44])
Output: cell of structures
result{2} =
chemFormula: 'Si3N4'
molecularWeight: 140.28
numberOfElectrons: 70
massDensity: 3.44
electronDensity: 1.0337
energy: 8.0478
wavelength: 1.5406
dispersion: 1.1164e-005
absorption: 1.6477e-007
criticalAngle: 0.27074
attLength: 0.0074403
reSLD: 2.9554e-005
imSLD: 4.362e-007
Example 2: >>result=refrac('SiO2',8:0.5:10,2.33)
Output: structure
result =
chemFormula: 'SiO2'
molecularWeight: 60.0843
numberOfElectrons: 30
massDensity: 2.33
electronDensity: 0.7006
energy: [5x1 double]
wavelength: [5x1 double]
dispersion: [5x1 double]
absorption: [5x1 double]
criticalAngle: [5x1 double]
attLength: [5x1 double]
reSLD: [5x1 double]
imSLD: [5x1 double]