X-ray Diffraction Simulation¶
Simulates single-crystal X-ray diffraction patterns. Activated by selecting X-ray in the Wave tab of the diffraction simulator.
X-ray source setup¶
Characteristic X-rays¶
Select an element and transition line:
| Element | Line | Wavelength (Å) | Energy (keV) |
|---|---|---|---|
| Cu | Kα₁ | 1.5406 | 8.048 |
| Mo | Kα₁ | 0.7107 | 17.479 |
| Co | Kα₁ | 1.7890 | 6.930 |
| Cr | Kα₁ | 2.2910 | 5.415 |
Synchrotron radiation¶
Set Element to 0 and enter energy or wavelength directly.
Camera geometries¶
In addition to a flat detector, the detector-geometry settings provide dedicated X-ray camera modes:
- Precession camera — simulates a precession photograph (single reciprocal-lattice layer).
- Back-Laue camera — simulates a back-reflection Laue pattern (detector on the source side of the sample).
Differences from electron diffraction¶
| Feature | X-ray | Electron |
|---|---|---|
| Wavelength | Long (0.5–2.5 Å) | Short (0.02–0.04 Å) |
| Ewald sphere curvature | Large | Small (nearly flat) |
| Simultaneous reflections | Few | Many |
| Scattering factor | Atomic f(s) | Electron fe(s) |
| Dynamical effects | Usually small | Large |
| Extinction rules | Strictly obeyed | May be violated by multiple scattering |
Intensity calculation¶
Kinematical theory is generally sufficient for X-ray diffraction (dynamical theory is available for electrons only).
Debye rings¶
Enable Debye rings on the toolbar for polycrystalline patterns.
- Ignore diffraction intensity: uniform ring colour
- Show index label: display indices near rings