Abstract
Neutron diffraction studies of metallic liquids provide valuable information about inherent topological
and chemical ordering on multiple length scales as well as insight into dynamical processes
at the level of a few atoms. However, there exist very few facilities in the world that allow such
studies to be made of reactive metallic liquids in a containerless environment, and these are designed
for use at reactor-based neutron sources. We present an electrostatic levitation facility, NESL (for
Neutron ElectroStatic Levitator), which takes advantage of the enhanced capabilities and increased
neutron flux available at spallation neutron sources (SNSs). NESL enables high quality elastic and
inelastic neutron scattering experiments to be made of reactive metallic and other liquids in the
equilibrium and supercooled temperature regime. The apparatus is comprised of a high vacuum
chamber, external and internal neutron collimation optics, and a sample exchange mechanism that
allows up to 30 samples to be processed between chamber openings. Two heating lasers allow
excellent sample temperature homogeneity, even for samples approaching 500 mg, and an automated
temperature control system allows isothermal measurements to be conducted for times approaching
2 h in the liquid state, with variations in the average sample temperature of less than 0.5%. To
demonstrate the capabilities of the facility for elastic scattering studies of liquids, a high quality
total structure factor for Zr64Ni36 measured slightly above the liquidus temperature is presented from
experiments conducted on the nanoscale-ordered materials diffractometer (NOMAD) beam line at
the SNS after only 30 min of acquisition time for a small sample (∼100 mg).
