NEUTRON-SCATTERING STUDY OF LIQUID-HELIUM - ANALYSIS OF NEW DATA

A new analysis of neutron scattering data obtained earlier for liquid He-4 is presented. The experiments were made on the time-of-flight spe ctrometer DIN-2P1 in the pulsed reactor IBR-2 The results are analyzed by using a consistent data processing technique including the represe ntation of the dynamic structural factor S(Q,omega) with a constant wa ve vector e. The one-phonon component of S(Q,omega) is approximated by using the damped harmonic oscillator function taking into account the instrumental resolution. It is shown that the experimental values of S(Q,omega) are in good agreement with the fitting model, i.e., have a simple one-component structure. The presented results indicate a pecul iarity in the temperature dependence of S(Q,omega) for liquid helium i n the wave vector region 0.5-0.8 Angstrom(-1). Various explanations of such a peculiarity are discussed. (C) 1997 American Institute of Phys ics.