PubMed Health⌕ Search

Biomedical subjects

U Bafile

Publications and source records attributed to U Bafile.

17 recordsLinked to original sources
PubMed2001

Neutron Brillouin scattering study of collective dynamics in a dense He-Ne gaseous mixture.

The dynamic structure factor S(k,omega) of a 77% He and 23% Ne gaseous mixture at T = 39.3 K and total number density n = 15.8 nm(-3) has been measured by inelastic neutron scattering at small angles. In the range of wave vectors studied, 0.7<k/nm(-1)<1.8, we find clear side peaks at frequencies following the hydrodynamic sound dispersion c k of the binary mixture (with c the adiabatic sound speed in the mixture). Surprisingly, neither fast modes nor a transition from normal to fast sound are observed in the above low- k region, indicating that hydrodynamic behavior persists up to k values which are larger than those predicted by theories and computer simulations.

Journal Article↗
PubMed1999

Structure of gaseous Kr in the low-q region by neutron scattering and interaction potentials.

Accurate experimental information on the long-range triplet interactions in noble fluids, as well as on the two-body potential, can be obtained from the low-density behavior of the static structure factor S(q) in the small-q region. The results here reported of a recent low-q neutron diffraction investigation in Kr, devoted to undercritical densities in the range 2.4<n/nm(-3)<4.3, provide important indications on the pair interactions and allow also a reliable analysis of irreducible three-body potential effects on the measured structure, from which the triple-dipole Axilrod-Teller strength is extracted with unprecedented accuracy.

Journal Article↗