Blurness of rings in electron diffraction

[hoshizora]

Hi guys,

I just did an experiment about electron diffraction the other day, and I had a really difficult time measuring the radii of the rings because they were quite blurred at the edges. Anyone knows why they are so blur, especially for the first (innermost) ring?

 

[Simon Bridge]

Welcome to PF;
The probably blur for similar reasons that the fringes in Youngs interference are blurry.

Does the theory predict definite clear boundaries for the rings?

 

[jtbell]

Anyone knows why they are so blur, especially for the first (innermost) ring?

It depends on the apparatus. Can you give us more details about the apparatus?