Measurement of spin-dependent total cross-section difference $\mathrm{\Delta }{\sigma }_T$ in neutron-proton scattering at 16 MeV

A new measurement of $\mathrm{\Delta }{\sigma }_T$ for polarized neutrons transmitted through a polarized proton target at 16.2 MeV has been made. A polarized neutron beam was obtained from the ${}^3\mathrm{H}(d,\vec{n}{)}^4\mathrm{H}\mathrm{e}$ reaction; proton polarization over 90% was achieved in a frozen spin target of 20 cm${}^3$ volume. The measurement yielded the value $\mathrm{\Delta }{\sigma }_T=(-126\pm 21\pm 14)$ mb. The result of a simple phase shift analysis for the ${}^3{S}_1{-}^3{D}_1$ mixing parameter ${ϵ}_1$ is presented and compared with the theoretical potential model predictions.