What Causes Scattering in Optics and How Does it Apply to X-rays?

[compro21]

You can put a diffuser in front of a visual light source (i.e. lightbulb) that will scatter light in all directions. In effect, the diffuser acts as an analog lightsource by making light go in all directions (some of the enegry will be absorbed). LCD screens use diffusers to spread out their backlight and give a more even lighting appearance. (The simplest example is a piece of paper in front of a lightbulb).

Anyway, I was wondering a few things: what optical property causes the scattering? is it Diffraction or Refraction? Does this same principle apply to higher-energy optics, such as x-rays? Would the same size diffusers work, or would they have to be thicker?

 

[mfb]

I would expect that refraction dominates for most setups.
For x-rays, you need materials which influence x-rays significantly. Many small crystals could work.