# Homework Help: Rutherford Scattering

1. Jan 30, 2005

### JamesJames

Calculate the Rutherford cross section for a 10 MeV alpha particle scattered at firstly an angle greater than 90 degrees and secondly for an angle greater than 10 degrees.

What does the relative magnitudes tell you in relation to the probabilities of the momentum transfer at large and small angles?

I cna calculate the cross section for those two values but what does the second part of the question mean? I am too confused about this part of the question. How does momentum transfer enter the Rutherford problem?

Any help would be greatly appreciated !

2. Jan 30, 2005

### Andrew Mason

I don't really understand the question, because momentum transfer is a function of the deflection angle. Momentum transfer depends on the deflection angle. The larger the deflection angle, the more change in momentum of the alpha particle (which is the amount of momentum transferred to the nucleus).

It would make more sense if the question asked how the probability of momentum transfer can be deduced from the relative scattering cross sections for the large and small angles. The ratio of cross-sections for a deflection angle of more than 90 degrees to that for greater than 10 degrees corresponds to the probability of large momentum transfer.

AM