Dan Hussey, National Institute of Standards and Technology
Abstract
Neutrons primarily interact with matter via the strong nuclear force (as opposed to the electron density) and so provide a complementary view of world to more conventional probes of matter. In particular, neutrons have a very high sensitive to hydrogen while being very insensitive to common metals such as aluminum. This has enabled neutron imaging to play a key role in understanding the water transport in hydrogen fuel cells. Neutrons can also be treated as waves and it is possible to construct a neutron Talbot-Lau interferometer to obtain phase and darkfield images which can increase the contrast for small variations in material density or porosity. An ongoing challenge in any neutron scattering or imaging measurement is the inherently low neutron intensity as compared to what is possible at modern x-ray synchrotrons. This is partly due to the difficulty in focusing neutrons as the refractive index differs from one by only 1-10 ppm. A new reflection base lens technology shows great promise to create the world’s first practical neutron microscope. In this talk, I’ll discuss how neutron imaging has benefited fuel cells and how it might be useful for lithium batteries, give an overview of the Talbot-Lau interferometer, and introduce the idea of the neutron microscope.