Neutron Imaging
Neutron version of radiography. This is a non-destructive method of visualizing the internal structure of a material by taking advantage of the high penetrating power of neutrons. It is possible to visualize light elements such as hydrogen and lithium, which are difficult to observe with X-rays and to map the residual strain and crystal structure inside a material by analyzing the wavelength dependence of the transmittance. The magnetic moment of neutrons can also be used to determine the distribution, strength, and direction of magnetic fields.
Snapshots of a water droplet on the sand. The time between the first and last image is 2.75 sec. Graphics from NMI3. The contrast is high because water (H2O) contains hydrogens while sand does not.