Experiment 2
X-ray Bragg Diffraction Simulator
Visualize how X-rays scatter from parallel crystal planes and identify conditions for constructive interference.
Simulation Controls
Key Equations
Bragg's Law:
2d sin θ = nλ
Constructive interference occurs only when the path difference 2d sin θ equals an integer number of wavelengths.
Interference Diagram & Intensity Profile
Task: Observing Bragg Peaks
Move the θ-slider slowly from 0° to 90°. Record the angles where intensity spikes sharply.
| Order n | θ observed |
|---|---|
| n = 1 | 15.8° |
| n = 2 | 33.1° |
| n = 3 | 55.0° |
Teaching Connection
Bragg's law is an elegant example of wave physics. How would you explain to a Form 3 student why scientists use X-rays rather than light to study atoms? What everyday analogy would you use for constructive interference?
Reflection Questions
- As plane spacing (d) increases, does the first-order Bragg angle θ₁ increase or decrease? Why?
- At what wavelength (λ) does diffraction no longer occur for a spacing of 2.82 Å?
- Why does visible light (λ ≈ 500 nm) not work for crystal diffraction?