Validity of the Fermi Approximation in Slow Neutron Scattering
Abstract
The correction to the Fermi approximation for the cross section is calculated for slow neutron scattering from a proton bound in a harmonic potential. For neutron energies up to fifteen times thermal energy, and for energy transfer due to proton transitions between the ground state and first excited state, the Fermi approximation is found to be accurate to 0.3%. This extends previous calculations, which have been done for dσdΩ, and which considered only elastic scattering from the proton initially in the ground state. This extension is believed to be necessary, because of the extensive use that is made of the Fermi approximation to calculate the energy distribution of scattered neutrons.
 Publication:

Physical Review
 Pub Date:
 August 1963
 DOI:
 10.1103/PhysRev.131.1153
 Bibcode:
 1963PhRv..131.1153P