The VULCAN diffractometer at Oak Ridge National Laboratory’s Spallation Neutron Source (SNS) was built to take measurements of engineered components like a jet engine turbine blade or the frame of a car. VULCAN can "see" inside the material and make three dimensional maps of the distance between atoms in critical sections. Scientists can use these maps to determine if the atoms are being squeezed together or pulled apart — signs of stress in the materials. This photo highlights the optical fibers of a VULCAN detector module. The fibers transmit light signals created by captured neutrons to photo multiplier tubes where the signals are amplified and then sent into a data acquisition system. | Photo courtesy of Oak Ridge National Laboratory.