Scattering of 1.32-Mev Neutrons by Protons

The total cross sections of polyethylene and graphite for scattering of neutrons of 1.315±{}0.003 Mev have been measured and are σ(CH₂)=(9.542±0.035)×10^-24 cm² and σ(C)=(2.192±0.020)×10^-24 cm². From these the hydrogen cross section is σ(H)=(3.675±0.020)×10^-24 cm². If the best current values of the binding energy of the deuteron (see [3]) the coherent scattering length (see [4]) and the epithermal cross section (see [5]) are used, the singlet effective range in the shape-independent approximation is (2.4±{}0.3)×{}10^-13 cm. This is to be compared with the proton-proton singlet effective range of (2.7±{}0.1)×{}10^-13 cm.