ORNL team performs first neutron diffraction experiments on a running engine Researchers at Oak Ridge National Laboratory (ORNL) have used neutron diffraction to provide noninvasive measurement of lattice strains inside components of a firing engine, thereby enabling the operando study of complex load states and thermal gradients throughout the solid materials. Their results are published in an open-access paper in Proceedings of the National Academy of Sciences (PNAS). Engineering neutron diffraction can nondestructively and noninvasively probe stress, strain, temperature, and phase evolutions deep within bulk materials. In this work, we demonstrate operando lattice strain measurement of internal combustion engine components by neutron diffraction.