INELASTICITY EFFECTS IN THE NEUTRON-DIFFRACTION MEASUREMENTS FROM WATER STEAM USING PULSED SOURCES

The problem of the inelasticity effects on cross-section data of molec ular systems measured at a time of flight spectrometer installed at a pulsed neutron source is addressed. The scattered intensity for severa l model dynamical structure factors are calculated and discussed and t he case of a water-like molecule is analysed in detail. The results ob tained using different approximations are compared with the experiment al cross-section data of heavy water steam in order to verify to what extent gas phase data can be reproduced. The possibility of using such calculations to account for the self scattering contribution to liqui d phase scattering cross sections is also discussed.