# What causes a plateau in the cross section of neutrons?

Tags:
1. Jan 17, 2016

### ORF

Hello

It seems to me that the nuclei have a flat elastic scattering cross section of neutrons, for neutron energies from eV to MeV.
http://www.nuclear-power.net/wp-con...attering-Cross-section-light-elements-min.png

I thought that maybe it was caused because the neutron interact with the nuclei as a hard sphere, so the (quantum) cross section would be 4*pi*r^2, but the I didn't see the correspondence between the nuclear radii and cross sections.

What causes that flat part in the elastic scattering cross section of neutrons?

Greetings.

Last edited: Jan 17, 2016
2. Jan 22, 2016