How to Correct for 3D Scattering in Rutherford's Gold Foil Experiment?

[thelibertine1]

Homework Statement

Hey. I've just conducted Rutherford's gold foil scattering experiment and am a little stuck on a part of the analysis. One of the objectives of the lab script is;

'To correct the counting rates measured in one plane for the fact that the foil scatters in a 3D cone'

So the detector only detects alpha particles in a line and doesn't account for others scattering above and below it. I've plotted the count rate as a function of the angle measured with the detector, how will this correction scale my results and how do I calculate this scaling factor?

Homework Equations

See attachment

The Attempt at a Solution

I attemped using a solid angle formula but got again stuck with not knowing the dimensions.

Thanks

 

[sgd37]

I don't understand what you are looking for, if you are looking for the stuff missed by the detector, that isn't a correction it's an extrapolation and in fact is the equation for the entire angle dependent distribution. I think you need to correct for the fact that your conic distribution was flattened onto a plane. So look at chords for circles

 

[thelibertine1]

Yes the conic distribution was flattened onto a plane, does that mean the count rate at each angle is actually less than measured?

 

[sgd37]

yes since that has the effect of bringing the points closer together

 

[thelibertine1]

So how can I work out how much less counts should me measured? Thanks by the way I think I get the idea

 

[sgd37]

well the ratio of the length of the plane and the corresponding segment of the circumference is pretty much the indicator. But I am not familiar with the geometry of your apparatus so I'm working on assumption here