Distinction of Liquid Water and Ice Based on Dual Spectrum Neutron Imaging

This study investigates a new approach to distinguish liquid water and ice based on dual spectrum neutron imaging. The imaging technique benefits from arising differences between the cross section of water and ice at neutron wavelengths above 3 Å. As a significant portion of the energy spectrum of the ICON beamline at PSI is below 3 Å, no differences can be observed with the entire beam. However, introducing a Beryllium neutron filter inside the beam, the interesting region of the spectrum is emphasized resulting in a significant contrast of approximately 1.8% between the aggregate states of liquid and frozen water.