Bragg diffraction
From Camilo's web

Introduction
Procedure
Results & analysis
The results of the measurement are shown in Figure 1 (below; note the error bars!).
We can identify clearly six peaks at 12^{\circ}, 20^{\circ}, 24^{\circ}, 31^{\circ}, 47^{\circ} and 59^{\circ}. Considering that the wavelength of the source used to measure the diffraction is \lambda=2.85\,\mathrm{cm}, we use Bragg's law to obtain the following values for the interplane distance d:
Peak position (^{\circ}) | Diffraction order (n) | d |
---|---|---|
12 | 1 | (6.12 \pm 0.25) |
20 | 1 | (3.77 \pm 0.09) |
24 | 1 | (3.17 \pm 0.06) |
31 | 1 | (2.50 \pm 0.03) |
47 | 2 | (3.53 \pm 0.03) |
59 | 2 | (3.01 \pm 0.02) |
The actual separation between planes is (3.80 \pm 0.05)\,\mathrm{cm}, from which we can conclude that the peaks at 20^{\circ} and at 47^{\circ} correspond to the first and second diffraction orders of the planes. The other peaks, therefore, must be due to reflections with other planes of the crystal.
Useful links
- The manual to set up the experiment is Media:Microwave-Optics.pdf here.