Erik Brubaker
Erik joined the radiation detection group at Sandia California in 2008 after beginning his career in experimental particle physics. He has served as PI on several neutron detection and imaging efforts, including the neutron scatter camera, time-encoded imaging techniques, and fast neutron coded aperture imaging. He has also led projects to investigate He-3 alternative thermal neutron detection methods, and a novel neutron imaging approach using crystalline organic scintillators. He has experience in data reduction & analysis, calibration techniques, and image reconstruction methods. He has a BA in physics from Lawrence University (Appleton, WI) and a Ph.D. in particle physics from UC Berkeley.
Possible Projects:
- RadMAP neutron background data: SNL installed and maintains 16 liquid scintillator detectors on the RadMAP mobile platform operated by LBNL/UCB. There is a large and increasing body of fission-energy neutron data for these detectors acquired over time in a range of locations and environmental conditions. Improving our understanding of neutron backgrounds and their dependence on external factors would increase confidence in verification measurements using neutron detection. A student would work to understand the variability of the fission-energy neutron background rates in the RadMAP data, and to what extent those variations can be predicted using independent information such as weather data, GPS, LIDAR, etc. Student responsibilities would also include data quality monitoring and occasional system maintenance or component replacements.
- Single Volume Neutron Scatter Camera: SNL has an ongoing effort to develop a double-scatter neutron imager where both interactions are detected in the same scintillator volume. Resolving and reconstructing the two nearby interactions using the isotropically emitted scintillation light is a challenging problem, and relies on photodetectors based on microchannel plates with excellent spatial and temporal resolution. Relative to current neutron imaging techniques, this approach would have strong advantages for treaty verification in terms of sensitivity and compactness. A student would choose from a number of hardware or analysis/simulation projects depending on interest and timescale.
- Advanced image reconstruction techniques: A student with strong interest in statistical techniques for image reconstruction would investigate, select, and implement a reconstruction technique with potential value for neutron imaging in the arms control context. Examples include reconstructing images using shape primitives as a basis space rather than traditional image pixels; fusion of gamma and neutron information in image reconstruction; and regularization terms for maximum likelihood that enhance features of interest.