The Dynamic Nuclear Polarization Program at ORNL

The ORNL High Flux Isotope Reactor’s IMAGINE instrument facilitates a wide array of single crystal macromolecular diffraction experiments. Notably, the neutron scattering experiments performed with this single-crystal diffractometer provide atomic-resolution insights into protein structure. The sensitivity of neutron macromolecular crystallography can be significantly enhanced by leveraging the spin dependence of the neutron scattering cross section of hydrogen. At ORNL, a proof-of-concept system employing Dynamic Nuclear Polarization (DNP) of samples has demonstrated a significant improvement in the signal-to-noise ratio of neutron diffraction data. Current efforts are focused on developing: 1) a highly polarized neutron beam with a high efficiency flipper; 2) a next-generation SiPM-based neutron detector array; and 3) a DNP apparatus consisting of a 5T Helmholtz magnet and a dry 1K ⁴He refrigerator. The progress and future prospects of constructing a new DNP-enhanced beamline will be presented.