Commissioning of the nddl-40 micro-channel plate neutron detector system at oregon state university

The Neutron Radiography Facility (NRF) at Oregon State University (OSU) has been modified to begin working on the non-destructive evaluation of concrete materials to study the early stages of shrinkage, cracking, and water transport of concrete during the curing process. The objective of this work was to investigate the efficiency and spatial resolution of the NDDL 40 micro-channel plate (MCP) detector for the use of neutron radiography and tomography to determine its applicability for examining concrete. Working in collaboration with the School of Civil and Construction Engineering, the NRF at OSU has added a NDDL-40 vacuum-sealed neutron imaging detection system with a delay line system readout developed by NOVA Scientific. This study found that the system installed at the NRF was capable of a maximum spatial resolution of ~250 μm with a neutron detection efficiency of 5.49%. Significant artifacts from the detector system and image noise degraded the quality of the tomographic reconstruction to such an extent that this neutron imaging system could not be used to visualize the desired phenomena in concrete.