Distance and pattern on Stern-Gerlach experiment 
On Stern-Gerlach experiment
Is their any experiment data showing the patterns for various distances from magnet to screen? I want to find out if the pattern smaller or not when the screen closer to magnet.
As you can see I need two different patterns. (Screen 1 and Screen 2)
 A: All experiments should have this feature. It is due to the fact that the magnetic field varies in the $\hat{z}$ direction (see the shape of the magnets), which in the picture is the upward direction and so different forces are exerted on different particles. A description of the force due to the magnetic field is given mathematically by
$$F_z = \frac{\partial (\mu B_z)}{\partial z}  = \mu \frac{\partial (B_z)}{\partial z} $$
where $\mu$ is the dipole moment.
As a result the particles gain a component of velocity in the z direction, as any spinning particle has a dipole moment. So the spread necessarily increases with more distant screens.
A: The figure above is quite trivial; when atoms are set on a course in a space with no further impulses, they follow that course. Assume that you filter out by blocking spin down atoms. The interesting question would be what happens if you put a second magnet a considerable distance away from the first magnet to check how fast the alignment of spin decays into random spin. When it is so easy to align the spin of the 5S electron, one would expect that even the interaction with other electrons in the same atom would cause an increasing decay over time away form aligned spin of the 5S electron.
