Homework Help: Determining nuclear radius by electron diffraction

1. Feb 28, 2007

dt19

can anyone explain to me, where does the equation $$R=\frac{0.61\lambda}{sin\theta}$$ come from when determining the approximate radius of the nucleus by electron scattering?

2. Mar 1, 2007

Edgardo

I think it has something to do with diffraction. Look up "diffraction by a disk".
I just read that it is possible to calculate the diffraction pattern behind a disc by Babinet's principle.

3. Mar 1, 2007

JeffKoch

sin(theta) = 1.22*lamda/D, from circular diffraction. D=2R, so R = 0.61*lamda/sin(theta).