Direct Measurement of the Spin-Dependent Capture and Scattering of Slow Neutrons byLi6

The spin-dependent capture cross section ${{\sigma }_{+}}^c-{{\sigma }_{-}}^c$ of slow neutrons ($\lambda =1.074\mathrm{}$ Å) by ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ has been determined from the flipping ratio of a transmitted polarized neutron beam as a function of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$ polarization. We used two methods, one of which also enabled us to measure the spin-dependent scattering length $b_{+}-b_{-}$ of ${}_{}{}^6{}_{}{}^{}\mathrm{Li}$. We find ${{\sigma }_{+}}^c-{{\sigma }_{-}}^c=-1170\mathrm{}\pm 50$ b and $b_{+}-b_{-}=(-0.38\mathrm{}\pm 0.05)\times {10}^{-12\mathrm{}}$ cm.