FINAL-STATE EFFECTS IN NEUTRON COMPTON-SCATTERING MEASUREMENTS ON ZIRCONIUM DEUTERIDE AND BERYLLIUM

We report inelastic neutron scattering measurements of the neutron Com pton profile, J(y), for Be and for D in polycrystalline ZrD2 over a ra nge of momentum transfers, q between 27 and 178 Angstrom(-1). The meas urements were performed using the inverse geometry spectrometer eVS wh ich is situated at the UK pulsed spallation neutron source ISIS. We ha ve investigated deviations from impulse approximation (IA) scattering which are generically referred to as final-state effects (FSEs) using a method described by Sears. This method allows both the magnitude and the q dependence of the FSE to be studied. Analysis of the measured d ata was compared with analysis of numerical simulations based on the h armonic approximation and good agreement was found for both ZrD2 and B e. Finally we have shown how (del(2)V), where V is the interatomic pot ential, can be extracted from the antisymmetric component of J(y).