The NBS-1 photo-neutron source is the primary standard for neutron calibrations in the United States of America. The source is constructed from 1 g of radium in a RaBr2 salt contained in a Pt-Ir capsule located in the geometric center of a 4 cm beryllium sphere. Since the source was fabricated in 1949, it is desirable to determine the integrity of the capsule and current geometry of the radium salt. Several challenges are presented in inspecting the source such as the high-Z materials used for the capsule which make X-ray tomography challenging with lower keV generators and the radioactive material which creates an intense neutron and gamma radiation fields. The radiation emitted from the source makes it impractical to move the source to a capable imaging facility and makes it difficult to work with as it is not possible to handle directly. To overcome these issues and allow for a feasibility study, a dummy source has been constructed using PbBr2 powder. This talk will provide background on the dummy source and the results of the feasibility study to determine if it possible to relocate a current X-ray system to the neutron calibration facility to inspect the NBS-1 source.

© (2019) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Jacob M. LaManna, Hans P. Mumm, and Maynard S. Dewey, "X-ray tomography of internal components of the NBS-1 photo-neutron source (Conference Presentation)," Proc. SPIE 11113, Developments in X-Ray Tomography XII, 111130F (Presented at SPIE Optical Engineering + Applications: August 13, 2019; Published: 17 September 2019); https://doi.org/10.1117/12.2529502.6084121100001.