Penumbral image source reconstruction with thick optics and uncertainty quantification

X-ray inspection systems often utilize highly-penetrating photon energies to pass through high-Z, thick systems. The LANL Microtron facility makes use of a 10-20MeV electron beam and converter target to produce high-energy photons of similar energies for this purpose. The source size, while sufficient for current uses, has not been characterized in detail. Recent work by Bachmann [1] images a 10–20 keV source with the use of both pinhole-based direct imaging with penumbral imaging. For higher energy systems finite thickness objects. We analyze a series of radiographic images obtained on self-developing films and image plates examining the effects of finite opacity optics. A Bayesian analysis approach is used to characterize reconstruction uncertaintites, similar to work by Bardsley, et al. [2]. Initial estimates of the source size indicate a Gaussian-like source with a distribution width of 1 − σ ≈ 379 microns. [1] B. Bachmann, et al., Rev. Sci. Instrum. 87 (2016) 11E201. [2] J.M. Bardsley, et al., SIAM J. Sci. Comput. 34 (2012) A1316.