High-Energy Neutron Scattering from LiquidHe4. II. Interference and Temperature Effects

The scattering of high-energy neutrons from liquid ${\mathrm{He}}^4$ was discussed in an earlier article on the basis of the Gram-Charlier series expansion of the incoherent scattering function. In the present paper, interference effects ignored previously are taken into account approximately and are shown to give rise to an oscillation in the half-width of the scattering function as a function of the momentum transfer. The temperature dependence of the scattering is investigated by deriving approximate expressions for the parameters in the Gram-Charlier expansion in terms of their values at $T=0\mathrm{}$, together with the observed thermodynamic properties of liquid ${\mathrm{He}}^4$. Reasonable agreement with the neutron-scattering data of Cowley and Woods is obtained.