# A Question about microwave diffraction (Bragg scattering)

1. Sep 22, 2008

### Jopi

Hi,

at my Uni we have a lab course where we first take some measurements and then write a report about the experiment. Our current experiment was about microwave diffraction. First, we measured the wave length of the microwaves, and then proceeded to measure the intensity of the scattered radiation as a function of the angle between the plane of reflection and the incident radiation.
We obtained a plot which shows clearly the maxima predicted by the Bragg law:

n $$\lambda$$ = 2 d sin $$\theta$$

The problem is that there are other maxima, which are not explained by the Bragg law. One of these maxima is actually higher than the one given by Bragg law. What causes these other maxima? Is it the reflection from other reflection planes? I've been trying to find about this on the internet, but so far I haven't found anything.