Small-angle Neutron Scattering Measurements of Liquid Helium Mixtures Confined in MCM-41

ORAL

Abstract

Small-angle neutron scattering (SANS) was used to study the isotopic distribution of liquid helium mixtures confined in MCM- 41, a silica glass with a 2D hexagonal net of monodisperse cylindrical pores, as a function of filling and He$^{3}$ concentration. The ordered pore array of MCM-41 gives rise to Bragg reflections with intensities determined by both how the liquid fills the pores and how the isotopes are distributed within the pores. The modulation in peak intensity can be modeled by writing down a form factors for cylindrical objects with varying scattering length density. Comparison will be made with small-angle X-ray (SAXS) scattering measurements performed with synchrotron light on liquid helium mixtures confined in aerogel.

*This work was supported by award 70NANB5H1163 from NIST, U.S. DOC. This Research at Oak Ridge National Laboratory's High Flux Isotope was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U. S. Department of Energy.

Authors

  • Helmut Kaiser

    • Low Energy Neutron Source (LENS), Indiana University
  • Timothy Prisk

    • Indiana University Department of Physics
  • Paul Sokol

    • Indiana University Department of Physics
    • Center for the Exploration of Energy and Matter, Indiana University, Bloomington, IN 47408
    • Department of Physics, indiana University
  • Ian Steward

    • Indiana University Department of Physics
  • Claudia Pantalei

    • Ecole Normale Superieure