Incident and scattered flux differential cross-section

8 Incident and scattered flux differential cross-section 

The incident and scattered fluxes are determined by the experiment. They are related to the previously defined collision amplitude. 

We associate a neutron flux with each of these states. The neutron flux operator at point r is 

Let us calculate the scattered flux, using the factorizations corresponding to the static approximation. The projection of the scattering state in real space is [see 

The scattered fluxes J,(r) are the measured quantities. However, they do not enter directly in the results because they depend not only on the incident flux J0 but also on the distance r between the nucleus and the detector. The differential cross-section characterizes more directly the scattering and the target it is defined by 

---