b'Flash Neutron RadiographyHigh-speed neutron imaging system enables science that was previously impossible.at the TransientF lash neutron radiography can visualize high-speed events that are impossible Reactor Test Facilityto see with other techniques. Visualizing bubbly flow at prototypical temperatures and pressures of a pressurized water reactor, for example, is not possible with any other technique. Previous attempts were limited by the available neutron beam intensity. During a power transient, the Transient Reactor Test facility neutron radiography beam is roughly 1000 times brighter than the current brightest neutron imaging beams in the world, representing a shining opportunity to establish unique experimental capabilities at INL. PROJECT NUMBER: 20A44-200 This project modified the neutron beam so it could be used during a transient and developed a high-speed digital neutron radiography system capable of frame rates TOTAL APPROVED AMOUNT:faster than 1 millisecond. To further improve the imaging system and more efficiently $1,046,000 over 3 years use the available neutrons, researchers developed neutron imaging scintillator PRINCIPAL INVESTIGATOR:screens using boron-10 that offer higher neutron detection efficiency compared to Aaron Craftthe most common neutron imaging screens that use lithium-6.CO-INVESTIGATORS: The reactor modifications are complete, operation of the beam during a Transient Shawn Jensen, INL Reactor Test facility transient is approved, and the flash neutron radiography system is William Chuirazzi, INL built. The first measurements produced a neutron beam flux of 7.710 cm-s- Joshua Gess, Oregon State University during the 7,800 MW peak transient, which is the brightest neutron imaging Wade Marcum, Oregon State Universitybeamline in the world. This neutron flux would be sufficient for frame rates of Burkhard Schillinger,~30,000 fps, far surpassing the current state-of-the-art of ~1000 fps. Technical University Munich This project represents a worldwide collaboration between INL, Reading Imaging, Steven Cool, DMI/Reading Imaging Oregon State University, and Technical University Munich. Several journal articles are published based on this project. This new high-speed neutron radiography capability represents a new state-of-the-art for high-speed neutron radiography that enables science that would previously impossible. Results from flash neutron radiography of a dosimeter acquired during a transient with a peak power of 7,800 MW. The camera sensitivity was at its maximum setting and the frame rate was 100 fps. The images saturate quickly during the measurement, demonstrating the potential to acquire images at ~30,000 fps with the peak neutron beam flux of 7.71011 cm-2s-1.34'